As for M Night Shyamalan's career being ruined by The Last Airbender, somehow I doubt it. The guy has given us stinker after stinker ever since Signs. He had a trilogy of hits with Sixth Sense, Unbreakable and Signs and then gave us The Village, which I quite liked but it is shit to be honest. Then it got even worse with the woeful Lady In The Water and I never even bothered with The Happening or The Last Airbender because I'd heard they were crap.
So hes had four crap films in a row going back 7 or 8 years, long before The Last Airbender. But the film he wrote and produced, Devil, did quite well and recieved decent enough reviews, albeit mixed and that was after four flops in a row so I wouldnt count him out just yet.