I support showing a superhero's origin if that superhero has never been on the silver screen before. Otherwise, it should be barred from any future movies featuring that character. Or at least done the way it was with The Incredible Hulk. Showing Spider-Man's origin for the second time in ten years in a film is just a waste of valuable screen time.
Not helping matters if they decide to cast a 27-year-old who looks like he's 35 to play Peter Parker. Andrew Garfield might be a good actor (I wouldn't know) but it's a bad bit of casting.