I didnt see one, but knowing FB it is f'd up. I read on the front page that they had an update to make it so you could use the messenger without actually having a FB account so maybe that is it
I think that "What's New" stuff is from the last version, it is the EXACT same list as the version from November 16th. I just hope it fixes the phantom notifications...
lol... no kidding... but actually, since I upgraded last night I haven't gotten a phantom notification but it might be to early to tell for sure because I have gone 12 hours without one before, will let you know.