We all know Nick Fury and S.H.I.E.L.D will be appearing in Iron Man 2. Heck, they were already around in the first movie and it got a nod in The Incredible Hulk. One of, if not THE most popular things involved with S.H.I.E.L.D is The Helicarrier. Well, The Helicarrier looks like it is definantly in Iron Man 2! The video game trailer reveals it, you can see it hovering in the sky pretty easily at 0:45 seconds!
Also, its been rumored that they were shooting top secret stuff with this green screen, and it has been mentioned by many that they beleive it is The Helicarrier!
I know this is not necessarily a confirmation, but it definantly gives hope!