There are so many great features in .Net 3.5 (LINQ, C# language features, LINQ, workflow enhancements, REST, LINQ, etc…..) that you would really like to use them in MOSS, right? Well, the problem is that MOSS is ASP.Net 2.0 based and by default you cant use these features. As it turns out, its fairly simple to turn on the .net 3.5 framework. Take a look at this article on Codeproject: http://www.codeproject.com/KB/aspnet/PMInSharePoint.aspx.
Thanks to Kirk Evans who pointed this out to me.