Nothing much other than entertainment!
G.I. Joe: The Rise of Cobra is filled with amazing special effects and practically non-stop action. Since it has action from the start to the finish, you cannot expect other things to be injected into this mindless entertaining movie other than special effects. Some of the action sets are stunning yet some were cartoon. I enjoyed Stephen Sommers' movies including the recent Van Helsing. His movies though lacked of a proper story line are at least interesting to look at.
The story: There is not much of a story; it is a race between the good and the bad. Duke and his friend Ripcord, join the mysterious G.I. Joe. Yes, there are some lame lines and some lame jokes made by Marlon Wayans, a guy who cannot stop cracking jokes even if there are some serious things going on. As you have seen in the trailers, this is practically filled with non-stop CGI and special effects, actions and gadgets, and yup cleavage too.
Overall: This is one of the movies you either like or hate it. I know this hasn’t well gone with critic. Critics hate movies like this. But we are audience. I like its over-the-top action, with things flying and exploding even this year Transformers 2 could not do so that much of action throughout the movie. You want great fun, catch this. Bring on the sequel.