Panasonic is the latest company to bow to Microsoft's exFAT filesystem for use in its products. exFAT (or FAT64) does bring a few evolutionary things to the FAT filesystem. The partition limitation is now 64ZB (64x2^70 bytes) and file size has been increased to the same limit. Older FAT32 partitions are limited to 4GB per file which is really unacceptable in today's computing world.
The problem with exFAT is that it is patent encumbered so any use of it requires a license to Microsoft. This should stifle industry adoption of the filesystem, but Microsoft is keen on pushing its technology into the market to lock out competing standards (like the patent free EXT4 filesystem or others). Microsoft has long learned to get its technology at the heart of products to force the market to adopt only its technology. exFAT is available on Windows, of course. Mac and Linux, not so much.
The new SDXC format for SecureDigital cards will be standardized on the exFAT filesystem. We have no doubt that open source support will move out of the experimental area soon enough, but standards should be open and not be patent encumbered.
In addition to licensing the exFAT filesystem, Panasonic also received a license for long file name support for FAT32. The full press release is on the next page.