I thought a new fresh thread is on order, you'll find much of the latest info in the first thread.
Official site with clips of the new Ultras and more-
http://www.capcom.co.jp/sf4/index.html
Release date(s):-
The game will be released Late April for all regions-
http://www.hadoken.net/?p=1163
New characters revealed: Hakan, Dudley, Ibuki, Makoto, Juri, Cody, Guy, Adon, T. Hawk and Dee Jay.
The game is stated to take place a year after SF4 and it is another tournament. In SF4, Abel was the main character as far as story elements go, whereas in SSF4, it's Juri.
The latest vids showcasing some of the new Ultras and more can be viewed here-
http://www.gametrailers.com/game/super-street-fighter-iv/12123
http://ps3.ign.com/objects/035/035905.html
http://xbox360.ign.com/objects/035/035904.html
http://www.gamespot.com/ps3/action/supersf4/index.html
http://www.gamespot.com/xbox360/action/supersf4/index.html
Gameplay changes expected to stay by final build-
Rose and ChunLi got better
Dan got a little better
Zangief, Ryu, Rufus and Sagat got nerfed, but I think they'll still be good
Guile's Flash Kick, FADC, Put on sunglasses is the new hotness
Some of the new alt. outfits-
http://apforums.net/showpost.php?p=1508480&postcount=287