Technically ultimate cool down has not been removed.
It has just been moved from Sorcery to Domination.
So as @ Hamstertamer mentioned, you could take Ultimate Hunter now instead of The Ultimate Hat and still get the same amount of cool down reduction as before.
The only problem is that now would have to go in to the Domination tree, instead of Sorcery just for getting the most amount of CDR.
To get the best out of your CDR focused build, you should take Transcendence rune from Sorcery. Because you will be leaving out some key damage items the conversion from cdr to AD or AP is really very crucial. Then you can still take Ultimate Hunter from Domination or Presence of Mind from the Precision depending on your champion.
Not that it's a good build on anybody, but in theory there's that.
It has just been moved from Sorcery to Domination.
So as @ Hamstertamer mentioned, you could take Ultimate Hunter now instead of The Ultimate Hat and still get the same amount of cool down reduction as before.
The only problem is that now would have to go in to the Domination tree, instead of Sorcery just for getting the most amount of CDR.