[babypuncher]

exFAT is a good candidate for a replacement "lowest common denominator" file system, and support for it is growing rapidly now that Microsoft has effectively open-sourced it.

But as you pointed out, in a transitionary period there is still a need to support older devices and software. FOSS purists may also not approve of using exFAT in some situations, since the relevant patents have not yet expired, even if MS has released them to the OIN.