Brady Forrest has a post entitled Two Weeks of MSN on MSDN where he lists a bunch of upcoming webcasts on about various APIs in the MSN Windows Live platform. Below is an excerpt of his blog post with the upcoming webcasts

MSDN Webcast: The MSN Search Toolbar: Building Windows Desktop Search into Your Applications (Level 200)
Monday, December 5, 2005
1:00 P.M.–2:00 P.M. Pacific Time

MSDN Webcast: Extending Start.com Using Startlets (Level 200)
Wednesday, December 7, 2005
1:00 P.M.–2:00 P.M. Pacific Time

MSDN Webcast: The MSN Search Toolbar: Tips, Tricks, and Hacks to the MSN Search and Windows Desktop Search Platforms (Level 200)
Friday, December 9, 2005
1:00 P.M.–2:00 P.M. Pacific Time

MSDN Webcast: The MSN Search APIs: Building Web Search into Your Applications (Level 200)
Monday, December 12, 2005
1:00 P.M.–2:00 P.M. Pacific Time

MSDN Webcast: Virtual Earth Tips, Tricks, and Hacks (Level 200)
Wednesday, December 14, 2005
1:00 P.M.–2:00 P.M. Pacific Time

MSDN Webcast: MSN Messenger: Extending MSN Messenger with Multi-Person Instant Messaging Applications (Level 200)
Friday, December 16, 2005
1:00 P.M.–2:00 P.M. Pacific Time

You can find more information on MSDN..

If you are interested in building applications that integrate with MSN Windows Live services and applications, you should definitely check out these webcasts. I'll most likely be participating in a webcast when we finally ship the MetaWeblog API implementation for MSN Spaces.