Steam Early Access Announced

Steam offers pre-release playability for select titles
Valve sent over a press release announcing that an Early Access section has been added to Steam's library of over 2,000 titles. Steam Early Access titles allow the community to get involved early and play select titles during their development. The goal of Early Access is to provide gamers with the chance to "go behind the scenes" and experience the development cycle firsthand and, more importantly, have a chance to interact with the developers by providing them feedback while the title is still being created.
To support the interaction between Early Access players and developers, Steam offers easy and automatic updating of games, letting developers iterate quickly to respond directly to bug reports and feedback from customers.