We're half way there now. Wakoopa provides a tool which tracks what you run. Register, download a small application and install. Wakoopa runs in the background and reports to Wakoopa's servers what you're running. I've installed this on my work machine (running XP Pro), go see what I use.
They don't provide the Windows to Mac switch recommendations, but you can see what other people are using and, perhaps, extrapolate from others what might work for you. If Wakoopa were to provide an API, then Apple could finish the job they never started.