Hot on the heals of the Windows 7 vs Linux link from the other day is the Lifehacker Windows 7 Versus Mac OS X Leopard feature by feature showdown.
Of course, as I've found, use whatever you want, and it's not just the features sometimes that make an OS a winner, sometimes it's the "feel" of it.
That said, still an interesting look, especially some of the features I didn't know were in Windows 7. Also you're comparing an OS that isn't out yet to one over a year old (wonder what Snow Leopard news will come out next week also).