I saw that too. Not sure what the Firmware update was.......as I didn't really check, but all seems OK with my RT. Gonna play around with it tomorrow and see what's new with 8.1
Yeah mine actually did download and install without issue. It just never told me it was doing anything which was disconcerting. Seems to be working fine.
P.S., Now I just need to figure out how to dump "Windows.old" as it it sucking up 7 gigs of SSD space..."
Run disk cleanup, after it calculates space, check "previous widows installations"