Microsoft has unveiled a new file format for end-to-end digital photography, called HD Photo, which offers better image quality, better preservation of data, and advanced features for digital-imaging applications. The company said this new next-generation digital image format provides the best solution for digital image editing and storage, and unleashes potential for digital photography on devices, applications, and services. Read more here.
Yes The HD format is already compatible with Windows Vista through the Windows Imaging Component (WIC) codec and can be also used on Windows XP or Windows Server 2003 if you install a free WIC utility. This format is also compatible in the .Net Framework 3.0 development platform and also available for Mac OSX.