And this is probably where I'd go into my speculation mode, but it's much too soon for that. Either way, it would make more sense for this to come out in October, no? --- http://www.youtube.com/watch?v=1au0xrhoxUo
October: LMDM Nomvember: WII U (Pikmin 3 / NSMBU / Etc.) December: PMSS January: ACJO --- Check out my daily topics on the Luigi's Mansion: Dark Moon board! Tell me if you think Luigi should be president! Agreers: 21
I don't know about the link posted, but I know that Wikipedia used to list DM's (okay, so technically, at the time, it was LM2) release date as November 18th... back in 2011. Maybe the writer just looked it up on Wikipedia when the data hadn't been updated as research. I checked just a minute ago, and it says TBD 2012, now, so who knows what's going on.
I definitely remember 11/18 being listed on the Wikipedia article, though...