Same here. I was really hoping for that, and I still think a game heavily influenced by Mirror's Edge will someday prove to be the breakout hit that ME wasn't -- Gears of War to ME's Kill Switch -- and a superhero game seems like a natural fit.
Either way, I really wish they'd give the game the time necessary to properly develop, and an open world game is obviously going to take a good deal of time if you want to give the world any detail and a sense of life.
Of course they'll put the game out alongside the movie whether it's ready or not. Activision should take notes from Arkham City -- the tie-in to the movie with a character as big as Spider-Man is a negative, not a plus, in just about every conceivable way these days.
And really, Spider-Man is quite similar in most incarnations -- movies, cartoons, comics... More so than Batman, I'd think, and as such, they're naturally going to gain from the movies' marketing efforts/popularity and take inspiration from them when it's advantageous to do so, but there is no need to handicap yourself by being attached to it.
A legit AAA Spider-Man game could be every bit as popular as Arkham City. Come on Activision, use your greed for good for once.