Not particularly new news now, but if you haven't started investigating PHP on Windows yet, here's your chance. Not only did IIS collaborate with Zend, they also made a download available for IIS 7 and IIS 6. From the news article on iis.net, looks like the effort is just starting - "This announcement coincides with a broader announcement regarding collaboration between Microsoft and Zend to improve performance and stability of PHP on the Windows platform."
Get the inside scoop, including configuration, performance and other goodies: http://blogs.iis.net/bills/archive/2006/10/31/PHP-on-IIS.aspx
Download it: http://www.iis.net/default.aspx?tabid=1000051
Follow the step-by-step downloading and installation walkthrough: http://www.iis.net/default.aspx?tabid=2&subtabid=25&i=1207