From the press release entitled Microsoft Unites Xbox and PC Gamers With Debut of Games for Windows — LIVE we learn

REDMOND, Wash. — March 14, 2007 — Microsoft Corp. today announced the extension of the Xbox LIVE^® games and entertainment network to the Windows^® platform, bringing together the most popular online console game service with the most popular games platform in the world. Debuting on May 8, 2007, with the launch of the Windows Vista™ version of the Xbox^® blockbuster “Halo^® 2,” Games for Windows — LIVE will connect Windows gamers to over six million gamers already in the Xbox LIVE community. Then, launching in June, “Shadowrun™” will for the first time connect Windows gamers with Xbox 360™ players in cross-platform matches using a single service. “UNO^®,” releasing later in 2007, will also support cross-platform play between Windows and Xbox 360.

This is pretty cool and I saw some of the demos when I was at CES in January. The funny thing is that one of my coworkers told me that we were announcing this soon but I thought he said "Games for Windows Live" so I thought he meant we were rebranding MSN Games. I didn't realize it was actually "Games for Windows — LIVE". This might get a tad confusing.