Pretty much what you'd expect = you knew it was coming... Let's say a lion is running towards you, you just watch and then, when it's close enough, jumps on you and eats you ! ... it's pretty much what you were expecting, right?, because, you know, it's a lion! (am I sutil or what? ^^ )

It means more or less exactly that. Exactly what you would expect.Usually from a type of person regarding their behaviour or attitude. 'It's pretty much what I'd expect from him.

Not exactly. :) "Pretty much what you'd expect." could be rephrased as "Nothing especially surprising or different." For example, if I saw an advertisement for a big action movie, and went to see it, I might say to a friend who asked me about it "Pretty much what you'd expect." What I'd mean by that is not much story or thought-provoking plot. Just a lot of guns and explosions. Does that help?

It's (just about/near to) what you would expect, but said with a hint of either uncertainty, or cynicism.