Not to nitpick, but is this supposed to be breaking news? Safari has been out on Windows for a while now - (since June according to Wikipedia).
To answer your question though, I'm sticking with Firefox on Windows. Installing Apple software on a Windows machine (including iTunes, Safari or Quicktime) brings with it too many auto-update/iPod assistant/"look-at-moi, look-at-moi" services that I neither want nor need. Plus, even when you uninstall the programs, they generally leave the auto-update stuff sitting around. I like Apple products, not a hater or anything, but I've got no time for that sort of thing. YMMV, of course - I'm a bit of a pedant when it comes to the number of services running on my XP machine.
I tried Google's Chrome browser too, which was quite nifty and innovative in its own way, but I got similarly jacked off with the uninvited Google Update service so I binned it. That one was actually a bit of a pain to get rid of! At least Firefox just does its thing and doesn't assume you want it to take over your system.