The Hobbit has done fine it was never going to make the stupid numbers fanboys were thinking. The draw is just not there for it too. It is not a flop or even a disappointment.
I don't think SkyFall will drop that much against Twilight. If anything I don't even see the hype for Twilight being that big. New Moon still holds the biggest pre-hype atmosphere of the bunch. It will do outstanding midnight's but from there it will act just like the other movies. No records and no legs.
QoS was very average. Casino Royale was very good and Skyfall is also very good but not as good as Casino. In my opinion. Bond movies don't really work like normal franchises. Every installment box office is dependent on the marketing and not really on its previous installment.