G.I. Joe 2 is officially happening, with director Stephen Sommers (an absolute gent) returning to call the shots, and Channing Tatum expected to reprise his lead role as the, eh, ponderous man of action.
A few months ago, Paramount tasked Zombieland writers Rhett Reese and Paul Wernick to bang out a screenplay, and were apparently so impressed with the outcome, they have pushed to have the sequel move as quickly as possible. The original also starred Joseph Gordon-Levitt, who we can't really see coming back in a supporting capacity given his current career trajectory. Sienna Miller and Marlon Wayans on the other hand...
Tatum is very busy at the moment, and these type of movies are normally in production for months, so a start date for shooting could still be as much as a year off.
