Updated the description with some core items that I feel Akali needs to buy since they were introduced in the last patch. Would update the items themselves, but they don't appear to be in the database yet.

Snowball items early aint realy viable because you never know the outcome of the game if you cant get kills you can benefit from the snowball items, i would recommend getting Rylai's befor any snowbal item or just dont get snowball items.(they are not constant)

Check out the new item.. Seems pretty much built for Akali.. (Lifesteal/spell vamp + an extra nuke w/ slow)

Oh and I also see that you do not have lich bane which imho is an absolute must. It increases your burst damage dramatically by making your hit after your ability do tons more damage :)

Very interesting build and I do like it a lot. However I Prefer to get Haunting Guise first thing....after the sword and pot that is, mostly because by then you can afford it and the extra spell vamp is helpful in early ganks. Also though most games never even last until a zhona's ring, I believe that a black cleaver would be more helpful, that way your mark of the assassin and your normal hit do more damage and you have a higher chance to get last hit in case all of your abilities are on CD or you've run out of energy. Other than that I like your build and mine is very similar :)