Interesting that there's new JpegXR APIs in Windows 8. Looks like they may be putting some real effort into supporting it (I haven't seen any from Microsoft for quite some time). Windows 7/Vista does of course support jpegXR as HDphoto, but it doesn't support the .jxr file extension recommended in the ISO spec. A small thing, but I imagine this would really put off camera makers and others supporting the format as if a camera produces a .jxr file, no computer will know what to do with it without installing extra software.
A little less important to most people.. but I found it a bit annoying that the build in jpeg-xr decoder in windows 7/vista doesn't decode all the images in the jpeg-xr test suite correctly. The ones it doesn't decode right are ones that use obscure colour formats, so it's not something most people would ever notice. But it does annoy me that if anyone else coded a decoder like this they would be liable to be sued for patent infringement by Microsoft as they would not be covered under Microsoft's "community promise" due to not completely implementing the jpeg-xr spec. Seems poor that Microsoft can't implement their own standard correctly on this one. Another issue with the decoder is, with certain images, it creates excessively large file sizes, with poor image quality. Comparatively, significantly worse compression than a jpeg. A bug like that completely defeats the point of most people wanting to compress their images like that.
Right now IE9 supports jpeg-xr, but so far they have not followed through and supported it in IE9 on windows phone. Given they got jpeg-xr support for free by using WIC on desktop for image decoding I wonder if they'll bother with the effort.
Interesting too to see jpeg-XR support in the next flash version. I'd agree it will probably sneak its way into CS6 too. I know adobe were actively working on native Jpeg-xr support in Photoshop for a while after the plugin by Microsoft was released, but shelved it after implementing jpeg2000 support and realising very few people used it yet still having to maintain the code for people who did. They were more cautious about support jpeg-xr allegedly after that.
Another cool project is a summer of code project to develop a jpegXR version of jibjpeg for use with firefox. Would be cool if we saw this grow into something usable in the near future. There seems to be a big lack of open source jpeg-xr decoders out there.