Have you ever not noticed something until someone pointed it out to you and after that you cannot stop seeing it? This video did that to me. Thanks a lot, Roger Ebert.
If you go back and look at every superhero movie released in the last fifteen years you will likely see the signature landing maneuver. It would make a nice drinking game for THE AVENGERS to see how many times Thor and Iron Man use the move (Note, JoBlo.com does not condone doing shots in a movie theater while watching THE AVENGERS. Please wait for Bluray and get sloshed at home).
It is obviously a more dramatic entrace to land in the Tebow-esque kneel rather than landing upright. Plus, it gives filmmakers the opportunity to act like true auteurs and get a nice female ass shot at the same time.