Updated at 5 p.m. ET with correction about how this feature works.
Microsoft finally shows some love to camera raw shooters, but it feels like more of a hug than a big, sloppy wet kiss. The company now offers a free download of Microsoft Camera Codec Pack for Windows 7 and Vista users that will render thumbnails and display previews of most popular raw camera formats. (A complete list is available at the download site.)
About mid-Vista vintage, Microsoft introduced its own "open" raw format that it hoped camera manufacturers would adopt for better integration with Windows, but the major camera companies tend to be notoriously proprietary about their raw formats and no one really raced to adopt it. The only notable cameras supporting it are/were the Nikon P6000 and P7000 with the NRW format. So I suppose we can take this as Microsoft giving in to the inevitable.
It didn't give in terribly gracefully, though. When you download the codec pack, you can immediately preview the images in Windows Live Photo Gallery. But in order to get the OS to display rendered thumbnails in Windows Explorer, you have to load them into the Gallery to force the OS to first create the thumbnails. This is a really clunky way to operate, and really annoying if you have images on removable media, since you have to import them to display them in the Gallery.