For RAW image support in Windows Vista, Microsoft is working with major camera manufacturers to help provide RAW image codecs for their respective formats so that you can view them in Windows Photo Gallery. As a matter a fact, several of those major camera manufacturers have already provided codecs for their RAW imaging formats:
- Nikon (.NEF files)
- Sony (.SRF and .SR2 files)
- Olympus (.ORF files)
Windows Photo Gallery has a "check for updates" feature that will kick in when any of the above file formats are discovered. Photo Gallery will prompt you for a update that will enable the use of these RAW Image formats from these manufacturers. More codecs are expected to come online and will be available via Photo Gallery's update feature, just as these are today. With respect to the Nikon files, there are apparently compatibility issues that both Microsoft and Nikon are actively investigating, with Nikon hoping to issue a updated codec in the near future.
The Photos and Imaging Experience Team explains the overall idea behind RAW format support in Windows Vista much better than I can (and far more in depth) in this post.
If you're experiencing issues with any of the released RAW image codecs or Photo Gallery, head over to the Microsoft Photography Blog and leave feedback there for the team, as they are actively reading comments and responding to users' needs.