The new 4th Edition Game System License ( 4E GSL ) will be released next week according to this WotC announcement.
D&D Insider, the online subscription based service for 4e has gone live, or at least its web site has. Features on offer include the D&D Character Visualizer and Character Builder for creating characters; D&D Game Table provides a 3D environment for online gaming; D&D Dungeon Builder for building dungeons (this is a free tool); D&D Compendium, a database of everything D&D; and Dungeon & Dragon online magazines. No news on pricing yet but the system requirements have been published. All that is required is a modest Windows XP SP2 system but there is no support for OSX or Linux.