http://geekswithblogs.net/AzamSharp/archive/2005/11/23/61046.aspx just read this to make me think about it.
Partial classes are NOT new people. They have been supported in IL since the 1.0 version of the framework. I personally think MS would have been far better off spending the 2 hours it took to implement this in C# to implement rethrow (which also has existed in IL without a C# construct) or static methods on interfaces which also fits the same order.
I find the example convoluted, if your classes are so big that you need to isolate them into 5 or 6 seperate files chances are its your design that has the problem. The thought that by putting my properties in one file, my methods in another, and my variables in yet another does not simplify the process since chances are if I am making any sort of substantial change to these items I will need to check out the lot of them.
I really hope this is not the best answer MS can come up with to make up for the lack of quality merging capabilities in VSS.
Excuse the rant.