I think that this would be very helpful, not only would it allow beginners to learn more about how others code, but it would also allow more advanced users to take this and make their own winforms controls and other such objects.  Many programmers learn by example, and this would be a great example, especially if most of the important comments were left in!

I learned alot more about arraylists and how to code one by looking through the java source code.  My vote is a strong yes!