^ You should rent or buy it. It's great fun. Don't expect anything of the calibre of Raiders of the Lost Ark or The Dark Knight, but it is a fun, feelgood comic adapation that deserved to do better at the box office.
The other thing about The Rocketeer is that it's very much in the vein of a Cap movie. WW2 setting, Nazi baddies, tongue-in-cheek, but not camp, respectful to its comic origins, patriotic without being cheesy and a lot of fun. So I hope JJ harkens back to it a bit when making Captain America - though this movie needs to be bigger, bolder and better.
On that subject, Timothy Dalton for the Red Skull, anyone?