Technically the N900 can boot NITDroid. Although version 0.8 doesn't have microphone support yet for calls (voice commands work though). And GPS apps like Google Maps works with an external bluetooth dongle.

Not sure if everything will fully work with NITDroid but they keep on surprising me with their progress. If they manage to get phone fully working (microphone doesn't work for calls), GPS, and Camera working then the N900 will have three operating systems to switch from. And only phone and GPS is really needed for general use (if you really need camera for non-spur of the moment photos you could just boot to Maemo or Meego if it works there).

But I doubt my personal dream will come. Having the N900 boot Maemo/Meego for desktop like apps (thru Easy Debian) and Android for smartphone purposes.