No company that I know of has produced any sample WAV's of choirs for the T2 yet.
Irishacts do superb samples for the Korg arrangers and keyboards and they are currently looking into the possibility of creating new samples for the T2.
If you look at http://www.synthzone.com/ubbs/Forum37/HTML/013806.html
you can go to their web site to hear the stuff they do for Korg and I should also add to that thread you are interested, as the more names the bigger chance we all have of getting a result. I'd buy some of their samples straight away if they did T2 sounds.
I should also load the PC editing software and play with that. I've created quite a few choir sounds which are far better than the internal ones. It's easy to use and the results if you put some time into learning how to use the editor can be fantastic.