I think it needs to be recognized though that most users are replacing Windows, and for various users and businesses, Wine can help support the transition by allowing unique or custom business apps to still be available under Linux. Linux can stand on it's own all it wants, but if users can't run the applications they need to then it's useless.
My historical complaint about Wine on Ubuntu was that it was always an old version, when the newer development builds gave a better user experience. Even with the latest build, there seems to be a wide range of experiences with Wine, while I'm floored at how well it runs most apps that I need to, I can appreciate that other apps don't work.
[BTW, FWIW I'm running Evernote 2.x, Mobipocket Reader, Firefox/Flash, Quicken... these aren't games, but they are still valuable apps to me, to say "nothing works" is a stretch. That being said, I think office/productivity application users might be more tolerant of glitches than game users... of course we had those on Windows too]