Why do I have a feeling that if they delayed the game another 2 years because of bugs, there would be equal uproar?
So I ask you, are you having fun with the game?
Also, to play Devil's Advocate against the whole "it's a map pack expansion."
Um.....what? There new guns, a new faction system, gambling games, new outfits, new story. The similarities include same engine and same background world. So by the logic that it is nothing more than an expansion pack, Oblivion was an expansion on Morrowind with better graphics, All of the Halos were map packs, same with COD. Half-Life 2, also just a map pack with new story. Hmm, all of the GTA's, map packs with Red Dead Redemption being a Western map pack. Assassin's Creed 2 just takes place in Italy, so that can't be a valid sequel either.
Tell me, what would have made New Vegas a good sequel or spin off then if not new quests, some new weapons and a different map. What more do you want?