The download isn't up yet, it takes some time to sign and virus scan an entire CD packaged up as a zip, but the site that details what is included is there!
Check out
http://msdn.microsoft.com/vbasic/vbrkit for all the details, and you can even order yourself a copy of the CD if you want to avoid the downloading hassles...
Quick highlights; a ton of free controls (not just trial editions) from Component One, Dundas, Infragistics, and Sax (Sax has provided a serial communication control!!!!), a pile of sample code, whitepapers and multi-media content as well.
Oh, and just a small point... all of the controls should work fine in C# as far as I know :)