I went to see this movie over the weekend and it's well worth the ticket price.
If you like Independence Day or Armageddon, you'll like this one. Even Matrix fans will probably enjoy it. While Skyline doesn't have the kind outstanding ensemble cast of the first two movies, there's a lot of potential to grow (and this is very definitely the first of several movies).
The special effects/cgi are amazing but the real interest is in the scenario itself. These are not unicorn-riding, Skittle-dispensing aliens. :D
This movie is too violent for the under 13 crowd and may have images that are too disturbing for some 13 - 16 year-olds. Sex and language problems are minimal for movie of this kind.