(Grumpy aside: the previews gave away a (different) plot point that was revealed only later in the movie. I suspect the impact would have been better if I hadn't seen the preview -- except that I wouldn't have gone to see the movie at all if I hadn't seen said preview. So you can't win.)
The movie was more action-focused than I'd expected; they could have included more of a look into the effects the problem was having beyond causing large things to fall down. I guess we know what demographic they were going for. :-) Still, it was a fun movie with some very funny bits tucked in among the more serious and predictable ones. Once they got the "you'll just have to accept this" premises out of the way, they stayed consistent and even had some good storytelling bits (like an apparently-trivial matter near the beginning of the adventure that factors significantly into the ending).
( premises you have to accept (mild spoilers) )
There were some nice touches, including referring to a bit of plot-essential technobabble as "unobtanium". In general, I thought the writers who actually implemented the outline they were given did a very nice job. Certain plot points, such as the fates of various characters, were obvious pretty much from the start, but this didn't diminish my enjoyment of the movie.
There was one big continuity glitch that would have been trivial to fix; I wonder how it was that no one noticed it. Oops. (It involves the number of sections in the ship.)
A small point: in the previews, I'm 99.9% sure that they showed the hacker kid saying that he's going to need a steady supply of Star Trek videos and Pop Tarts. In the movie, it's Xena videos and Hot Pockets. Faulty memory, product placement, or something else? (And, the kid isn't savvy enough to ask for DVDs? :-) )