This is the reason why we don't have a Korra commercial! If anyone is interested, here is the registration for usage of the name "Avatar: Legend of Korra" on TV. Here is the one for "The Last Airbender: Legend of Korra".
An interesting thing to note is that "Avatar: Legend of Korra" has been put into the "Intent to Use" section on 10-03-11, after SDCC. "The Last Airbender: Legend of Korra" is also in the "Intent to Use" section, but it was placed there 8-30-11, so a little after SDCC. Neither of them are registered at the moment. Once one registers, that WILL be the title, no matter what.
Another interesting thing to note is that Viacom has requested an extension on the name "Avatar: The Legend of Korra" and changed the address of further correspondence in November 2011, but did not do this with "The Last Airbender: Legend of Korra".
This is why we got nothing at the end of December. Nickelodeon cannot show commercials or use the name of the show (whatever it is) until a title gets approved and registered by the USPTO. SDCC is different because it is not on the air and it's merely teasers and building anticipation at a panel with a "working title" which was "TLA:LOK" at the time and there was no monetary gain.
I think all we are waiting for Korra to premiere is the darn legal stuff to get straightened out!
(I kinda wish I researched all of this beforehand. So, in the end, it is not Nick's fault they aren't advertising it. It's the legal process' fault!)
But we should have one by February 1st because that's when the license expires.
Found out this info on ASN: link (third to last post)
Please stay civil. You should not harass other users or their views.