Ilia Iordanov wrote a very detailed article about the Attached properties in Silverlight 2 Beta 1. You can find almost everything you ever wanted to know about them in it.
Jonas Follesoe talks about the programmatically generation of DeepZoom images.
Take a look at this DeepZoom sample made by Mike Ormond.
Ronnie Saurenmann from the Swiss DPE Team has made three video tutorials. The first is about using WCF and LINQ to Connect a DataGrid to a SQL Database. The second is split in two parts and focuses on CRUD operations using Silverlight 2 Beta 1 - Part 1 / Part 2. The third part explains the scrolling through large resultsets with Silverlight 2 Beta1 and LINQ to SQL.
Jeff Brand made a video tutorial how to directly download videos from Silverlight Streaming. You can find it here.