There's been quite a bit of work done on the Flash Player to display and export JPEG-XR files. During the Flash CS6 prerelease, the Flash team talked about additional JPEG-XR support for things like spritesheet creation.
I know there's an ancient Photoshop plug-in for JPEG-XR, but does Adobe have any plans to make JPEG-XR a first-class citizen in Photoshop? Considering the numerous benefits the format offers, I'm puzzled as to why this hasn't been added.
Either way, it would be helpful to get the scoop. If there are no plans to support it then I'll buy a product that does, but I'd prefer Photoshop.
I've been using XnConvert to convert uncompressed files to JPEG-XR. It's a free, cross-platform, batch file converter:
XnConvert doesn't have as much control over compression settings as I would like, but the JPEG-XR files it creates are 30% – 50% smaller than comparable JPEG files saved using Photoshop's "Save for Web".
For anyone interested, Microsoft just released a new Jpeg-XR Photoshop plugin that costs with CS5 and CS6:
It seems rather nice.