I've been working on getting FSAA (the ARB_multisample extension) working with the glControl.
I feel like I'm pretty close but using SetPixelFormat to set the 'format' variable to the format I get back from Wgl.ARB.ChoosePixelFormat does not seem to have an effect.
I'm using the NeHe example and applying it to OpenTK. In WinGLControl.cs: c_HandleCreated() I prepare and create the context normally, then use the Wgl.ARB.ChoosePixelFormat function to get back a pixel format with 4 samples. I get back '32' at this point for the format. I then call PrepareContext and CreateContext again, passing in the pixel format.
It doesn't seem to have any effect, however, but I feel like this is kind of on the right track. Any pointers? :)
I can create a patch tomorrow if anyone would like to see what I have so far.