Enterprise Library
Jonathan Wanagel gives word in a comment about the Enterprise Library. The library is announced on MSND Patterns & Practices and a GotDotNet workspace was created a few days ago.
The first version of the Enterprise Library is being developed by Microsoft in partnership with Avanade. Early 2005 it's said to be released to the public, although Avanade's enterprise customers will have a late 2004 release to work with. Check out the workspace to find out how to participate in the review process.