Another related thing that was revealed: actresses were not too prominent in action movies of that same period, because the category for Best Actress: Action Adventure looks back a little farther to Abigail Breslin in Nim's Island, Rachel Bilson in Jumper and (whoah, December? that was so long ago) Diane Kruger in National Treasure: Book of Secrets.
Other movie awards will be presented separately in comedy, drama, horror/thriller, "bromantic comedy" and chick flick categories, plus breakthrough performance and best villain. There are also awards given for TV, music, sports, fashion/beauty, comedy and youth service. You can see all the nominees at the TC08 website (or in this PDF file) and if you're an actual teen (aged 13-19), you can also vote (actually, you can lie about your age -- I'm in my 30s and I voted).
Then tune in to FOX at 8pm (ET) on August 4th, to see if your favorites win. The telecast will be hosted by Miley Cyrus (aka Hannah Montana).