As mentioned
here, they are not trying to come up with a clever name for the version after Vista. Some people are complaining already about naming an OS around a version number but... OS X? Hello? OS 10.
I've also seen complaints that the kernel is reporting 6.1. This is by design, and it is due to the amount of programs that will downright break if a major version number incremented.
I'm glad they are moving away from year based names, too.