Some of the coverage and top stories so far: 

http://www.gamasutra.com/php-bin/news_index.php?story=23568
http://kotaku.com/5248907/thief-4-its-official
http://www.joystiq.com/2009/05/11/eidos-montreal-confirms-thief-4-worst-kept-secret-in-industry/
http://www.gamespot.com/news/6209475.html
http://www.shacknews.com/onearticle.x/58567
http://www.escapistmagazine.com/news/view/91613-Thief-4-Its-Official
http://g4tv.com/thefeed/blog/post/695427/Thief-4-Officially-Official.html
http://www.mcvuk.com/news/34248/Thief-4-emerges-from-the-shadows
http://www.1up.com/do/newsStory?cId=3174158
http://www.computerandvideogames.com/article.php?id=214694
http://www.jeuxpo.com/afficher_news-17424-thief_4_est_confirme.html
http://www.jeuxvideo.com/news/2009/00033963-thief-4-annonce.htm