In the light of Microsoft announcing that they are open-sourcing the .NET framework[1], I think it will be really beneficial if you put your controls on GitHub, so the community can participate in the development. 
For example interested parties could implement solutions for more advanced scenarios themselves (I know you guys have to prioritize your work), instead of using ugly workarounds in their code. There are many cases where support for these scenarios is more appropriate inside the controls. Presently, any effort I would make with the provided source code for current release would be wasted when the next release arrives. Also, open discussion on how would be best to incorporate new features in the overall architecture would benefit everyone.

Another way of looking at this is when .NET becomes well supported on other platforms (Linux, OS X, ...) it would be hard to port your controls without the help of a larger team. The Linux community in general is especially proactive w.r.t. open source projects.

I hope you can agree that open development (discussions, code reviews, contributions, etc.) will give you a strong competitive advantage.

[1] http://blogs.msdn.com/b/dotnet/archive/2014/11/12/net-core-is-open-source.aspx