There is a minor update to PC Companion software, but except for slightly larger icons there are no discernible differences, as pthwaite wrote. (it's still V1.0)
UPDATE: The "Merge" is much improved! I guess I jumped the gun 
It's still kinda ugly with black bars replacing the strokes BUT they are scaled correctly, so now it's actually USABLE. Still PDF only, no support for images.
As for any firmware update: this may or may not have occured on some readers, but if the firmware #s are what dlb wrote, they are the same as the ones that came pre-installed on the reader (you can check the screenshot in my "Unboxing" thread) So nothing new there either.
UPDATE: It seems the slightly newer PC Companion update checks for the firmware now. If it is launched from the reader, nothing happens for now (it's the same #). If it is launched from a cardreader, it's not able to match up the firmware #, so it starts (re)downloading it on the card. When you then insert the card in the reader, it will initiate a firmware "upgrade" (see photo), but all the #s remain the same as stated above.
metadata.db files are not much to go by since they are constantly being updated by the reader and presumably the PC Companion software.