Ok. I caved and saw it this weekend. Ann & I were downtown after Ann's 10K race, took care of some wedding stuff, then said what the hell and saw a matinee.
I'm glad I did, but not for the obvious reasons. Let me explain. (These reasons might come out disjointed, so bear with me)
It is not like the Star Wars movies have been great works of art or cinema. You can't compare SW to LotR, but the inevitable comparisons are there. Jackson took immaculate care of Tolkien's work. Lucas was trying to bring is own imagination to the screen. I give Lucas credit... he has envisioned a world and universe that is captivating for lots of people. However, he struggles to bring it to the screen. But the vision is there, and it really is quite grand (if Lucas had given up control over the dialog and direction, and stuck with production, these films would be insurmountably better).
If you treat all the SW films as serials... Like the SciFi short stories written in the 50's by Asimov, etc., these are good movies. The dialog doesn't matter... hell, the plot is secondary. What was important was the vision of the world and conveying that to the reader. Lucas succeeds at that with Revenge of the Sith (I would argue he failed with Episodes I & II, but I don't want to delve into it).
Picture a Shakespearian Tragedy... Swap out all the dialog with 50's SciFi serial writing... Combine it with the intense pace of Cameron's Aliens... and then darken the consequences even more, and you have Episode III. You may still cringe (I know its hard to express emotion behind a black hard plastic mask, but come on! What's with the "STELLA!!!" Couldn't you come up with something better?) but its worth seeing it if you have seen all the previous 5 films. This is obviously the pay off. Don't deny yourself it. Go see a matinee. The only way to really appreciate the film is on the big screen. Trust me on that one... don't wait to rent it... it won't be the same film.
Christensen is better in this film (which I know isn't saying much.. but I also don't think he's been given much to work with up until this point). Ewan McGregor and Ian McDiarmid do their best to save the film. Lucas ruined a great chance for McDiarmid to shine, but fucked with his voice (you'll know the part). He already has an awesome voice (with two ends of his inflection... don't screw it up with extra processing).
When you compare the CG between Episode I and Episode III, you can see the tremendous improvement. In Episode I, the CG sets were bland, and you just wanted to cry out... WHY IN HELL didn't you just build sets for crying out loud!!. In Episode III, you don't notice nearly as much that all the acting is done on blue screens.
I'll have more thoughts later... But my advice is to see it. See it on a big screen. Its worth the price to see the vision... even if occasionally you cringe at its presentation.