At the Worldwide Invitational in Seoul, South Korea Blizzard today announced a follow-up to the original Starcraft, and it is not an MMO as some had anticipated. IGN has live coverage from the show, including some in-game screenshots. The Starcraft2.com site has just been updated with new content, including the intro movie shown at Blizzard's WWI in Seoul.
Update: Some users have reported problems with Blizzard's torrent downloader, so here is the torrent file, extracted from said downloaders, so you can use them in your torrent program of choice. Cinematic Trailer 69.4MB, and Artwork Trailer 27.6MB.
Update2: Gameplay videos are now available, in 1280p and 720p resolution. 449MB and 268MB respectively.