First off, thanks for the offer -- it's generous, and very useful IMO. It certainly sounds interesting, and I would like to take a peak at the code. The big problem I have with WineSetupTk it's that it's written in Tcl/Tk (I suppose). I don't know the language, and I don't care to learn it. Moreover, I think Wine should use itself for such tools, so we get to use all the nice controls we have <g>. One thing that I'd like to see is a programs/winesetup utility that's based on WineSetupTk, but it's written in C, with the Win32 API & Controls.
I believe Alexandre plans to have Wine configured via the registry eventually. Then it would probably make sense to have a C program that acted as a control panel applet and did what WineSetupTk does, but in a dynamic fashion using the registry APIs. Until then I would expect a C version of WineSetupTk to be rather ugly from having to deal with much text config parsing and manipulation.