This plug-in is a file format plug-in to enable Adobe Photoshop to open and save HD Photo files.
Updated versions of the HD Photo Plug-ins for Adobe Photoshop for both Windows and Macintosh OS X are available now. There is an updated beta for Windows Vista and Windows XP, plus a new beta for both Intel and PPC Macs running OS X.
The encoder options dialog box, has been separated into the basic and advanced controls in two separate modes. This is more consistent with similar dialogs in Photoshop.
There is also some other re-arranging and general clean-up of the dialog user interface, with better consistency among related controls. The pixel format control will now only offer the pixel formats that are compatible with the current image mode in Photoshop.
There is also a major architectural overhaul of the underlying codec and memory management. These changes significantly reduce the memory requirement to encode and decode an image, improving performance and allowing support for much larger images without encountering memory limits.
source: Bill Crow's Blog.
This BETA plug-in is designed for use with the CS2 or CS3 versions and will expire after December 31, 2007. HD Photo is also known as Windows Media Photo.