I think movies use a lot of creativity when they are making these movies. I do not think 2012 was at all that realistic in terms of the things that happened. Armageddon was possibly slightly more so in that a comet could hit Earth, and we would know it was coming. However, we would not be able to blow it up with a nuclear bomb, it is simply too big. One thing we could do is attach some rockets to one side of it, and try to push it slowly out of the way. We would have a few years to do this, so it is possible.
I agree with Steven and Ed, the movies aren’t all that realistic. The only thing realistic about 2012 is that the Mayan calendar ends on that year, and this has caused some people to think that the world is going to end. What a crazy conclusion when there are so many better explanations – like, maybe the Mayans just didn’t feel like they needed a calendar update for a time as far ahead as this?