Edin Kadribasic has posted on his blog about a new compile of PHP 5.2 he's created using a new offering from Microsoft:

I have just completed the first build of the current php-5.2 CVS using the new compiler from Microsoft. The file is avaliable at php-5.2.1RC2-dev-Win32.zip.

The comments on the post indicate a possible problem (run time error) in the build, but no response yet on if it has been worked on or not.