How cool is this?
Experience the web, Apple style, with Safari: the fastest, easiest-to-use web browser in the world. With its simple, elegant interface, Safari gets out of your way and lets you enjoy the web -- up to 2 times faster than Internet Explorer.
Assuming the rendering and scripting engines are reasonably consistent between the Mac and Windows versions of Safari, it looks like you might not need a Mac anymore to test your Javascript code in Safari! Of course, you still might (should) want a Mac, but that's a different issue entirely.
I downloaded it, and my first impressions are pretty good. Looks good, runs fast. Only thing missing are some Firebug-caliber debugging tools. If we get that, Firefox could potentially get knocked out of the top stop as my favorite browser in which to write and test Javascript code.