http://uk.xbox360.ign.com/dor/objects/902601/tom-clancys-splinter-cell-conviction/videos/splintercell_trl_stealth_62909.html

Looks incredible. Hopefully out September, I'm not sure if these are the actual release dates, the internet may have lied to me.

UK / Continental Europe
25 Sep 2009
United States
20 Oct 2009
Australia
T.B.C.

Australia always gets the shit end

Also:
http://uk.xbox360.ign.com/dor/objects/902601/tom-clancys-splinter-cell-conviction/videos/e3live_splinterconvition_p1.html
and
http://uk.xbox360.ign.com/dor/objects/902601/tom-clancys-splinter-cell-conviction/videos/e3live_splinterconvition_p2.html

Demo part 1 and 2.