Windows Azure is the name Microsoft has given to the cloud based platform. If you're not at PDC (like me) then go here for more information: http://www.microsoft.com/azure/services.mspx.

"The Azure™ Services Platform (Azure) is an internet-scale cloud services platform hosted in Microsoft data centers, which provides an operating system and a set of developer services that can be used individually or together. Azure’s flexible and interoperable platform can be used to build new applications to run from the cloud or enhance existing applications with cloud-based capabilities. Its open architecture gives developers the choice to build web applications, applications running on connected devices, PCs, servers, or hybrid solutions offering the best of online and on-premises."

Looks like my personal point of interest, Live Mesh, is part of this platform:

"Live Services includes Mesh technologies for synchronizing user’s data and extending web applications across multiple devices."