I was thinking... How plausible would it be to use some of the voicework elements from the Clone Wars CG cartoon series in replacing some of the dialogue in AOTC and ROTS? The actor who plays Anakin on the show sounds a pretty good deal like Hayden Christensen, and there's an entire TV show's worth of dialogue to pick and choose various snippets from. Obviously by far and wide most of Christensen's original dialogue would probably remain in tact, but the option is at least there to maybe swap out some of the stuff that does work (or was just plain horrendously acted) with something that does work.