Part of my http://wiki.winehq.org/UnitTestSuites effort is to make it easy to write scripts that automate the building of windows apps on wine or windows interchangably.
After a while of writing special purpose tool-install-scripts that would work on either wine or windows, I realized that I really just wanted winetricks to be my tool install script, and that it should run on windows. i.e. if you want firefox on windows or wine, you should be able to do "sh winetricks -q firefox" and have it appear. Likewise, if you happen to need the Windows 7 SDK for something you're building, you should be able to say "sh winetricks -q psdkwin7" and have it appear, no questions asked. (Assuming on windows that you have cygwin installed, of course.)
So I'm starting to make that happen. Firefox works, psdkwin7 is not quite working, and lots of verbs that run windows apps still need their paths converted, but it shouldn't be hard to get your favorite verb working in both OS's now.