An image from the cache of the LEGO site and visible at this address
http://cache.lego.com/images/shop/prod/10221-0000-xx-12-1.jpg currently circulating and provoking heated debates.
So it looks like the next UCS set carries the reference 10221 and we get an ultra-detailed Executor accompanied by a slew of minifigs and a scale Star Destroyer.
If criticisms are already pointing to the design of the craft, everyone agrees on the choice of this vessel for a self-respecting UCS set. It remains to know the price and the date of availability (October 2011?) .....
Edit of 12/04/2011 at 23:40 pm: The page is no longer visible on the LEGO site.