Think about it. A Governor is recalled and then, a short time later, his replacement is in the basement as well. Then there's North Dakota where everyone has a 115% approval rating.
A lot of it has to do with climate: economic, cultural, political. California is a disaster, and the politicians are going to get the blame. There may never- and I literally mean never- be another widely popular Governor of California.
I somehow doubt this. The major problem that Schwarzenegger is having is probably, in my view, that he has promised to do everything he isn't. He promised to be a moderate voice that bridged the partisan gap, but has not really managed to do so, particularly when it comes to the state legislature. Californians are, to an extent, realizing he isn't a silver bullet.
I'm not sure this is entirely fair to Ah-nold, though, and he is probably being held up to a higher standard than most politicians would be. Still, though, I suspect that Californians are holding him up to that standard, and he is failing to meet it. I take these poll values at relative face value because of this, and believe there is a distinct posibility that Californians may vote out Schwarzenegger because he fails to meet these inflated standards.
By the way, while California is certainly economically troubled, I would not call any three of those things a "disaster." It is, by and large, a very cool state that is rather screwed up.