New Skins in the Store

Lord Darius
Blackthorn Morgana
Tyrant Swain

PvP.net v1.60

Normal Draft Mode
Normal draft has changed so that premade groups are not prioritized over solo players
Solo players have a 20% chance of being the team captain with banning powers and first pick, regardless of the premade status of the rest of the team
If a solo player is not team captain, the player will be given a random slot in the pick order
If players group up before a game, their host absorbs all of their chances, i.e. the host of a 4-man premade has an 80% chance to be captain
Ranked Solo/Duo Queue
The Free to Play rotation has been removed from Ranked Solo/Duo Queue
Unlocked Champions that appear on the Free to Play rotation will still be playable
You may now rename your buddy groups by double-clicking the name of the group
Fixed a bug where some buddies would appear to be level 0 with no information
Fixed a bug where the sound at the end of Champion select would play too loudly
Fixed a bug where swap offers in Champion select would persist into your next game

Balance in all things.

League of Legends v1.0.0.140
Darius, the Hand of Noxus

Hemorrhage (Passive) - Darius aims his attacks strategically, causing his target to bleed. This effect stacks up to five times.
Decimate - Darius swings his axe in a wide circle. Enemies struck by the blade take more damage than those struck by the shaft.
Crippling Strike - Darius's next attack severs a crucial artery. As the target bleeds out, their movement and attack speeds are slowed. Crippling Strike's cooldown is lower the more bloodied the target.
Apprehend - Darius hones his axe, granting him passive armor penetration. When activated, Darius sweeps up his enemies with his axe's hook and pulls them to him.
Noxian Guillotine (Ultimate) - Darius leaps to an enemy Champion and strikes a lethal blow, dealing true damage. This damage increases for each stack of Hemorrhage on the target. If Noxian Guillotine is a killing blow, its cooldown is refreshed.

Ashe

Ashe's art update
New model for Classic Ashe
Updated and improved models for Woad Ashe, Shewood Ashe, Frelijord Ashe and Queen Ashe
All new animations and updated VFX for base and skins
Updated splash art
Hawkshot now displays total gold retrieved by the skill in the tooltip
Adjusted Frost Shot's projectile speed to match the basic attack projectile speed
Fixed a bug where Frost Shot's attack frame was slower than the basic attack

I largely like the cosmetic updates. The Frost Shot projectile buff is a very good change, in my opinion. Slight usability buff.

Caitlyn

Fixed a bug where Caitlyn would appear to attack during Ace in the Hole

Yay, bug fixes.

Cho'Gath

Rupture
Added red/green rings to indicate which targets will be affected
Launch delay reduced to 0.65 seconds from 0.7 seconds

Slight usability buff, and very slight targeting buff for Cho'Gath. A good change, in my opinion.

Dr. Mundo

Sadism now returns 40/50/60% of Mundo's health instead of 40/55/70%

Mundo will still be Mundo. A decent nerf to his late game, but he'll still be incredibly difficult to kill once he gets items, partly due to his passive.

Fiddlesticks

Dark Wind now deals 50% increased damage to minions

A slight buff to Fiddlesticks. Very needed, in my opinion. It will mostly help his jungle, though it might also help his laning a bit (not that very many people lane Fiddle anymore).

Fizz

Fixed a bug where Playful / Trickster would prevent Fizz from casting spells for longer than intended

Bug fixes are good.

Gangplank

Parrrley now displays total gold earned by the skill in the tooltip

Yay, interface buffs.

Hecarim

Rampage damage to minions increased to 66% from 50%
Devastating Charge now requires less distance traveled to get the full effect

I worry about these buffs for Hecarim. His early game is fairly weak, but once he gets a few items, he's one of the strongest tanky bruisers in the game right now, in my opinion. We'll see where this goes. It seems a lot of people still don't know how to play the centaur reaper.

Lulu

Glitterlance
Damage adjusted to 80/125/170/215/260 from 80/130/180/230/280
Ability power ratio reduced to 0.5 from 0.6

More nerfs to AP lulu, while leaving the rather obnoxiously strong (opinion) support lulu alone. Doesn't make complete sense to me.

Malphite

Health per level increased to 90 from 82
Increased Malphite's travel speed during Unstoppable Force

Slight buffs to Malphite. Not needed, in my opinion, though not game changing in any way, shape, or form, either.

Morgana

Soul Siphon Spell Vamp reduced to 10/15/20% from 10/20/30%

Late game sustain nerfs to Morgana. Riot really doesn't like sustain, it seems. Possibly unnecessary, though they really don't change the ridiculous utility that Morgana brings to a team.

Nautilus

Fixed a bug where Riptide would continue to deal full damage on subsequent hits to slow immune targets

Bug fixes are good.

Renekton

Cull the Meek's fury-enhanced swipe trail is now properly red

Visual bug fixes are also welcome.

Twisted Fate

Loaded Dice will now show total gold earned by the skill on a per-unit basis on the buff tooltip

More interface buffs \o/

Xin Zhao

Fixed a bug where Three Talon Strike did not take Critical Damage modifiers into account

A bug fix, and a slight buff to Xin's damage output.

Items

New item: Athene's Unholy Grail
80 Ability Power
36 Magic Resist
15 mana regeneration per 5 seconds
15% cooldown reduction
Unique Passive: Restores 12% of your max mana on kill/assist and increases your mana regeneration by 1% per 1% mana missing
Phantom Dancer movement speed reduced to 12% from 15%
Zeal movement speed reduced to 6% from 8%

I like the Zeal and Phantom Dancer nerfs. The items provided an obnoxious amount of kiting and chasing power to anyone in possession of one (or more). The Grail also appears to be a very cool item for champions that go through mana rather quickly. Anivia comes to mind, and Galio as well, as every stat on it is put to optimal use.

Summoner's Rift Graphics Updated:

New textures across the entirety of Summoner’s Rift
Changes to the color palette to differentiate the upper and lower jungles from one another
A new shopkeeper has arrived to service all your Champion’s item purchases
New animations on many monsters including the Ancient Golem, the Lizard Elder, and Baron Nashor
HUD now displays the number of creeps you have killed
Minimap has improved so that map icons and player icons display more clearly
Significantly improved game performance on low end machines and at lower quality settings
Improved the visual quality of the in-game HUD

Over all, I like the new visuals. Some of the textures do seem a bit too cartoony for my taste, such as the new shop, but otherwise, I really like the changes.

Co-op vs. AI

Bots will no longer kill themselves by chasing enemies onto the summoning platform
Fixed a bug where Shen Bot did not learn all of his abilities
Fixed a bug where Ashe Bot would occasionally get stuck toggling Frost Shot repeatedly
Fixed a bug where Bots would use Cleanse on knockup, and knockback abilities

Yay, AI

Spectator Mode

Spectators can now view the spectator UI and use Timeshift controls after the game has ended
Spectator Mode will now run at full speed when alt tabbed in windowed or borderless mode
The mouse cursor will now hide in spectator mode after a period of inactivity
The spectator HUD will now remember chat visibility settings between games
Significantly reduced CPU usage of the Featured Games module
Improved the algorithm for selecting Featured Games to include more Normal and Ranked Team games with extremely skilled players
Fixed a bug that caused Featured Games to occasionally show completed games
Fixed a bug where fast forwarding up to live could break spectator mode
Fixed a bug that could cause Directed Camera to miss kills in some situations

Yay, spectator mode updates!

General

Towers will now alert you with a tone and a particle when you are being targeted
Added a confirmation dialog for the quit button in champion select for Custom Games
All spells attempted to be cast while crowd controlled (stunned, snared, etc) will now cast immediately at the end of the effect
Improved particle scaling on characters like Dragon or Baron Nashor
Fixed a bug where players could not spam emotes to their heart's content
Fixed a bug where units would remain highlighted after death
Fixed a bug where inputs made while the shop is open would translate onto the battlefield (unintentional pings, pathing, etc)

Yay, emote spamming is back! I'm a bit worried about the spell casting after CC ends, however. I feel like this could cause some issues.