Quickly: great effects, good acting, bad science, meh movie.
Summary: Global warming causes the next ice age. That's basically it. You follow the story of a few groups of people and how this affects them then it focuses in on one family.
The Good: the effects were great, from ice falling on people in Japan to the frozen Statue of Liberty. You can tell this was the main focus of the movie and they do a good job. The acting was rather good in this, and I had no complaints about any performances. The pacing was also good, as I wasn't bored at any one point.
The Bad: the preaching. I knew it would be there, but things like the 'evil' vice president giving the 'save the world' speech at the end when he was proved wrong was too much. The fact the plot eventually switched to just the one family and really just the Father trying to save the son was pretty typically Hollywood lame. The father making up with his wife was worse. The plot was alright but really, it's just a giant effects movie, there isn't much meat.
The Ugly: the science. I don't know much about weather patterns and such but this was just hokey. The wolves! Why?!?
Overall: not the worst I have ever seen, but no where near the best. A typical effects blockbuster and don't expect any more then that. It was OK, the effects were cool, the acting was good, the science was suspect and the plot was contrived.