If you've seen any of Roland Emmerich's previous disaster titles, you probably know what you're in for with this one. That being said, I felt 2012 had better acting and a more exciting storyline than the others.
In order to enjoy this film, you have to ignore the ridiculously absurd premise about neutrinos and the sun catastrophically altering the earth's crust (forget about the Mayan prophecy, which is hardly mentioned). If you can overlook why the world is ending, this is actually an captivating film with some spectacular effects scenes. Yes, there are several perilous close calls that stretch the notion of "luck". Yes, the actors from all parts of the world become interconnected in what stretches the notion of "coincidence". No, it's not going to receive any best acting or screenplay nominations. Nevertheless, it's engaging.
Cusack is great as the everyman hero. Ejiofor grabs your attention as the young government scientist trying to prepare for the inevitable. Glover and Harrison are also effective in smaller roles: Glover as the resolute President, and Harrison as the wackjob conspiracy theorist who might not be so crazy after all. Many other characters are merely stereotypes (like the Russian) or one dimensional (like the wife), but let's be honest, it's not the characters that we're coming to see. If you are, you'll probably be disappointed.
2012 is not great but it entertains as a doomsday thriller.