Well, I just got back from seeing this, and have a few comments. First off, I really liked the movie. The movie was far from "unfunny". I will say that the script felt slightly off. I can't pinpoint what it was specifically that seemed that way, but it wasn't the jokes or the story. As for the 3D, I was rather disappointed after having experienced Beowulf in 2007. With this, the 3D was very inconsistent. There were times when it looked fantastic and was easy on the eyes. There were other times, however, that the effect was very imperfect and the viewer is left struggling to focus on the subject of the particular shot. It really makes me eager to see what James Cameron has in store for Avatar, where so much care has been paid to make the 3D work as intended.
A few more minor things. Seth Rogan's blob, Bob, totally made the movie. The vast majority of his jokes and gags were hits, with only a small handful being misses. He definitely made the movie. Another was Susan. For some reason, there was something incredibly hot about a 3D, 50 foot woman, especially in the beginning when she first transforms. Galaxar reminded me of Barak Obama for some reason. I don't know what it was, but he just looked like I imagine Barak would look like if he had four eyes. The arrogance and narcissim were difinitely there.
All in all, I'm giving this a 7/10. That score may go up after I get to see it a second time on Blu-Ray in 4 months.