It seemed really short. I was amazed. Part of that was the ending, which didn't seem like it was winding down (or even really coming to a climax) until it was already pretty much over.
I can see the first three episodes, jointly, being a kick-ass eight-hour movie. It makes me more prone to forgive Episode One, and Episode Two has been much more tasteful and hearkens back much more to its roots. These are movies which, with a sufficiently cool Episode Three, really could culminate in the older three Star Wars movies.
They'll still make odd back-to-back viewing but overall I'm quite impressed. I'll probably go see it again, which is more than I expected.