I've been watching lots of the video sessions from the PDC that I missed and have found a good set to watch for those interested in Data Services.  By the way, this whole new AtomPub/REST way of exposing data services not only enables the consumption of data in the cloud, but I believe will be the standard way we approach DAL tiers for all applications in the future (well at least until the Oslo repositories become realities).

 

Watch these sessions in the following order:

 

The first three will give you a good introduction to Data Services and the REST protocol.  The last three apply these concepts to cloud computing.  If you get really interested in this topic, further discovery can be found in the sessions related to Astoria Offline Data, Oslo, and of course all of the Windows Azure sessions.

 

Also, here's the official ADO.NET Data Services page on MSDN.