Microsoft unveiled an ambitious new trendy Web 2.0 platform and services dubbed Live Mesh.

Live Mesh is the brainchild of Ray Ozzie, the new chief software architect at MS and was apparently 2 years in the making.
Microsoft's "Live Mesh" uses the Internet as a data hub and synchronizes files across computers, phones and other devices.
Live Mesh is open to all developers as it is supposed to be cross-platform and cross-browser. It will be based on standard protocols and feeds the Web 2.0 crowd embraces like Http, RSS, REST, ATOM, JSON and FeedSync.

Microsoft plans to release Live Mesh in a widely-available test, or "beta" version before the end of 2008.
More details in this earlier story and on ZDNet. ZDNet also has a couple of screenshots of Live Mesh.