Wow, I was just thinking of this, and here I find the thread was brought back recently.
Yes, kegs are very much needed. Or at least some way to make barrels that will only be used for alcohol.
The problem is this: Food builds up and lies around your fortress. Even when you run out of barrels, your farms keep producing food, which builds up and spams jobs saying "HEY, PUT ME IN A BARREL!" So you end up with several hundred plump helmet roasts demanding to be placed in a barrel.
And, meanwhile, your stills just shut down with a cancellation message... and when you try to build more barrels to solve the problem, all those piles of hundreds of plump helmet roasts (which have been building up in the meantime) spam far more jobs than your small number of stills. No matter how many barrels you make, if your farm is producing too much food, you can't keep up -- food is just much better at grabbing barrels than booze is under the current system.
So, long story short, we need a way to make barrels that only our stills can use. Kegs would be a good way to do this and could solve other problems besides (like the absurd amount of time it takes to drink).
Of course, you can partially solve this by making a big drinks-only stockpile (it will claim barrels, which will then only be used for drinks.) But anticipating the need for this requires pretty detailed knowledge of how barrels and jobs work on the part of the player, and is a bit counter-intuitive.