It seems to be official now. no Xbox Next unveiling at Game Developers Converence.

http://xbox.ign.com/articles/583/583891p1.html
http://news.teamxbox.com/xbox/7557/I...-Xbox-2-at-GDC
http://www.reuters.com/newsArticle.j...technologyNews
http://xbox.advancedmn.com/article.php?artid=4089

It'll happen at E3 though.