I like how modular it is.  I would like to try it but replace the source control with subversion with SVNBridge (http://www.codeplex.com/SvnBridge).  I think the most interesting would be the code analysis reports they provide.  Here is a Free Book on Team Development with Visual Studio Team Foundation Server (http://blogs.msdn.com/robcaron/archive/2007/08/06/4270609.aspx).

I have heard about Eclipse as a frontend to Team Systems (http://www.teamprise.com/), but this (http://ropeonfire.blogspot.com/2007/11/monodevelop-and-team-foundation.html) is the first I have heard about MonoDev on Team Foundation

Have you ever wondered what FXCop static code analysis rules does Microsoft have turned on internally? (http://blogs.msdn.com/fxcop/archive/2007/08/09/what-rules-do-microsoft-have-turned-on-internally.aspx)