Ok... so I'm biased here, Pedro used to be my grand-boss at MSDN, and now works on some very cool and very graphical magic as part of the Whitehorse team... but on the side it appears he has been developing some Windows Forms controls, so I would suggest you check them out;
This ControlLibrary contains subclassed WinForms controls that I've been working on. It contains the source code as well as the test apps for them. The controls currently supported are: ImageComboBox, ImageListBox, FlatTabControl, and FlatComboBox. All of the controls support design-time functionality and support from their base controls. The changes have been mostly to the way they're painted. The source code for this library is also up on the following workspace: http://www.gotdotnet.com/Community/Workspaces/Workspace.aspx?id=b2de7aa8-4123-46ce-ae5a-08d059657165. Use the BugTracker there to report any bugs. Also, I discuss some of the interesting points in the code on my blog at: http://darthpedro.blogspot.com/.
Fun MSDN search fact of the day: We have a MSDNTV episode on "Whitehorse", it is even listed here, but searching MSDN on the word "Whitehorse" returns only one result... and it isn't the MSDN TV episode with that exact word in its title... it is a timezone article (America\Whitehorse is a defined timezone)... nice.