Against my better judgment, I went to the theatre this week to watch 2012. My (short) comments below will include spoilers; if you intend to watch this movie and think that knowing some details about the plot will detract from the experience, skip the next three paragraphs (also... really? you'll watch this movie for the plot?).
In short: great CG, no plot. No need for a plot, one can argue. Sure, the movie does make a token attempt at explaining why is it that the Earth will be destroyed, but it felt a bit like that was tackled there after the catastrophes had already been decided on (major widespread earthquakes, California sliding into the Pacific, gigantic tsunamis) - the "weird neutrinos" explanation takes up some 30 seconds of a 151-minute movie, so you can guess how important it is to the story.
The odd things is that what really annoyed me about the movie is... John Cusack's family lives in Los Angeles, and he takes his kids camping in Yellowstone. That's a 1,700km drive. With two young kids in the car. No frakking way.
Other than that, if you ignore the carefully choreographed destruction scenes, the slow-motion collapsing buildings, the tsunamis showing up in deep waters and the continents moving over 1500 miles in one night, there are really not that many places to play the "scientifically inaccurate" card against the movie. Not that it is accurate (far from it), but if you're going to accept the main premise, you're in for everything else. As a colleague said: sit down, turn brain off, enjoy the effects.