Of coarse Threepio could've been used for comic relief again in EP1. The Gungans could've just been background characters like all of the things in the cantina and we would have cared for them just as much.
Lord of the Rings has showed us all what kiddie stuff Star Wars really is, and we should've viewed it as that in the first place. If that were so we wouldn't be so disappointed by the prequels.