Safari 3 for windows http://www.apple.com/safari/
Although only beta it’s a start. I remember this time last year looking for a windows KHTML or WebKit browser and could only find the swift browser which at the time was very buggy. Since then I think it’s changed hand and probably still worth a look.
For me this is great news, no longer do I have to keep on checking browsershots or browsercamp even time I make a slight change to my css or html. I know it probably wont render exactly as it does on the mac but still it’s a great start.