There's actually been talk of a live-action G.I. Joe movie for about 3 years now. There
have been 3 animated DVDs released in the past 3 years, as well as the (horrible) Sigma Six series on TV.
I think they're going to take a "wait-and-see" approach with the upcoming Transformers film - but I think a G.I. Joe flick would do really well -
and I'd love to see it.