Merging patch content into the master files is how they've always updated the game in the past. Expect this to continue being the case in the future too. So long as it doesn't turn into the nightmares I've read about NV getting totally screwed up by it.
The December update also brings some unlisted bug fixes to the game. A lot of players were complaining about crashes and lockups after the November patch and this update should alleviate those issues. 2b1af7f3a8