Try this link
for a listing of Vegas places. And I think the SonyStyle at Ceasers Palace, will probably have them too.
Oh, and I think next week is the CES
in Las Vegas, and I believe I recall (from when I saw them in Austin at the end of October) that the Sony Marketing folks were planning to attend, so you might have a chance to run them down and talk to them directly -- you have to share what you find out if you do!