The new Windows build page http://valokuva.org/magick/ contains builds for both Imagick and Gmagick. All builds are done using VC9 and PHP 5.3.
ImageMagick builds are QuantumDepth 16 (default).
GraphicsMagick builds are QuantumDepth 8 (default).
Please note that these builds won’t work with the official PHP.net binaries which are compiled using VC6.
Edit: Pierre corrected me that there are official VC9 builds of PHP available at http://windows.php.net/download/