Apple has just released a beta of Safari version 3.0, for Windows (as well as for OS X) as shown at the WWDC keynote earlier today.
From my experience, it is kind of buggy and systems with less than 1.5gb RAM dont want to run it, every page increases RAM usage a bit, for me it is around 400MB right now.
Of course, when I tried to post this from Safari the text box didnt appear, WC devs have something to work on

Download: http://apple.com/safari