Games For Windows Live, the new service that integrates Xbox Live functionality with Windows PC games, is set to launch May 8th, alongside a port of the classic Xbox title halo 2. Major Nelson lays out the details:

Silver Membership Features

Single gamertag

Common gamer profile

Common gamerscore

Single player achievements

Private chat via text and voice

Common friends list and online presence

PC only multiplayer including browsing a list of active PC games



Gold Membership Features

All Silver membership features PLUS

Multiplayer matchmaking with friends

TrueSkill matchmaking

Multiplayer achievements

Cross-platform gameplay

It's an interesting idea but I doubt it will gain much traction beyond people who already pay for Xbox Live (who will get to use GFW Live for free). How important is being able to play against Xbox users to PC gamers?