A Rollicking Fun Space Opera ---major spoiler warning---
I've just came back from the theatre, and I must confess that this is one of the most fun films that I've seen in a long time. The film starts on a very large space battle, in which Palpatine has somehow gotten himself captured by Count Dooku.
There is a very interesting interaction between Christopher, Hayden, and Ewan, during the battle. Christopher Lee says a line that I think was delivered just great: "Twice the pride, double the fall", which really predicts what happens to Anakin.
Some of the dialog is delivered a little clumsily, but Ian McDiarmind doesn't muck up any of his lines (and some are written a little badly, I admit) and is really the saving grace of this film, even if you hate all the rest.
Anakin's slow fall into the dark side is really well done, and you just want to scream has he does some of this more insidious deeds you just know he has to do.
The final battle between the two friends is very emotional. Ewan's final lines about Anakin being the chosen one, are well delivered, also.
About the CGI: Some really great work with the space battles this time around to be sure, and General Grievous was very well animated. Anakin's transformation into Darth Vader is very chilling and painful to watch, and effective.
About the Music: John Williams really outdid himself! The final battle music takes bits of "Duel of the Fates" and fits it into the new music, which includes a lot of choral vocals, and is very chilling.