One of TFNs sources this weekend tells us about their perceived impressions of how Episode III plays out in its current state based on the inside information they have:
Everyone is expecting a full blown Star Wars movie - maybe even all action from the sound of it so far. Well, that's actually not the case. It follows a very close structure to Episode II, so I hope you liked that film. There's plenty of action at the beginning, kind of a slow middle then an amazing last hour and ending.
I know this isn't exactly a revolutionary report, but I wanted fans to understand it isn't all action throughout the entire film - there's plot development in the first half of the film for a while then it really heats up. But hey, we get wookiees and Jedi fighting together, so that has to be cool, eh?