I'm at the cinema watching it and had to take a break halfway through. It's pretty intense, non-stop fighting and evading aliens.
Regarding meteors, they came without warning, appearing suddenly and started their descent to Earth. However, these "meteors" seem to be under intelligent control, as they slow their descent, once they get close to impact. They hit areas in the oceans, near largely populated areas. But instead of being meteors, or evenly cleverly disguised missiles, they are actually transport vessels for invading forces.
At this point in the movie, it appears to be a colossal recruitment advertisement for the US Marines.
Aliens in this movie are assumed to be colonizing the Earth, removing or destroying the indigenous population, to secure our resources, which we are told is most likely our water (although I'm only half-way through the film).
I'm a little confused as to the psychological intent of this movie. It certainly portrays aliens as a nasty, destructive force in our universe.
If the intent is to trivialize meteoric bombardment to distract attention away from their real threat, I don't think they'll succeed, as a negative association will be made nonetheless.
However, this certainly is a distraction from threats internal to the human race by redirecting attention onto the other, the outsider. If that is the intent, then they could very well be successful in their efforts. The concept of alien, the outsider, can always be used to fuel xenophobia.
Gonzo