I just returned from an afternoon showing of Revenge of the Sith and I while I can't rave about it, I can't rightly complain. Lucas finally nailed a prequel and I couldn't be happier. The dark path to Vader is plausible and well articulated. Ian McDiarmid is a utter delight to watch, as is Ian McGregor. Even Christian Hayden isn't replusive. Go figure!
If only Lucas had taken as much care with the setup of the first two films as he obviously took with this one, the world would have been a much more entertained place. No spoilers, but it does appear that Lucas preps the story to dovetail nicely with Episode IV (including that pesky android problem). Without question, this was film had Jar Jar's best performance. And yes, I think it would take about 20 years to build a Death Star. I live in city that's been building a couple of highways for just about that time, so I'm used to big budget government projects that drag on for years.
George Lucas, I salute you!