On the subject of previous backstories from the 70's, I seem to recall reading in one version of the opening crawl/prologue about Mace Windu and his master from such and such planet. Obviously Lucas changed it all around and retained only the character's name by the time he wrote TPM, but it's yet another planet name he could have used. Instead he kept going back to Tatooine and Coruscant for what seems like half of the entire trilogy. That's one major fault of the PT, Coruscant is like this HQ which the characters can fly back and forth between. That's BORING. TPM isn't quite as guilty of this, but it did spend a bit too much time on Tatooine. I remember feeling kind of dissapointed when I found out Anakin was from the same damn planet as Luke. I think it was on the OS sometime before the movie was released. Everything on Naboo and Coruscant works just fine, although again I wonder why the Jedi Temple was there and not on some other planet. Yes, I know it's all a part of their downfall as an Order, but it's yet another step towards making the universe feel very small and closed off.
As for AOTC, well, I don't really know where to start. This is where the PT starts to feel like a TV miniseries more than an actual trilogy of movies. It was only a gearing up for the Clone Wars, and the only good stuff is at the Battle of Geonosis. Besides that, it serves to set up Uncle Owen and Aunt Beru just so we know who they are at the end of ROTS. Speaking of which, on to that film.
My biggest problem was the ending, would've liked to have seen only the fight between Anakin and Obi-Wan for those ten minutes. Cutting away to Yoda and Palps was just an excuse to lessen the quality of both duels. Again, it's too much about Coruscant. I also remember hearing that Anakin would be collecting various pieces of the Vader armor throughout the film, too bad. The Vader armor just felt really tacked onto the ending of the movie. With the flip of the swithc we go from PT land to OT land.