This E3, Epic Games made two major announcements across the Microsoft and Sony press conferences.
First, Gears of War for PC has been officially announced (no surprise there). The game will ship sometime during the fourth quarter of 2007, will feature cross-platform online multiplay courtesy of X-Box LIVE and Games for Windows - LIVE. The PC version of the game will support DX-10 for better visuals than the 360 version, will ship with one new multiplayer mode, a new Single-player chapter featuring a stalking Brumak and several new multiplayer maps. Probably most important about the release, however, is that Gears for PC will ship with the Unreal 3 Engine's development package and appropriate Gears of War assets. This will allow your Average Joe to make use of the incredible development system and produce mods to enhance or augment gameplay. Awesome.
Secondly, Mark Rein took the stage during the Sony press conference to announce that Unreal Tournament 3 will ship for both PS3 and PC this year, will support cross-platform multiplay, and will maintain that exclusivity well into 2008. In addition to that, Rein announced that for the first time in gaming history, a console (the PS3) would be able to support mods for UT3 made for the PC version. If you don't realize the significance of that, well, it's monumental.