Yes, there will be an official Green Lantern movie, according to IMDB, but it won´t be going to the big screen before 2011, directed by Martin "Casino Royale" Campbell.
YouTube user jaronpitts couldn´t wait: he created his own fan trailer, using plenty of scenes from other movies (you will easily recognize which ones; jaronpitts himself lists all of them in his YouTube page, which doesn´t do anything to spoil the surprise you´ll have with the high quality of the job) and recreating in CG classic lanterns as Kilowog. Enjoy!
Ha ha! Excellent job. Got to love that. :)
Take care,
L.
That is a real good trailer! I think I need more information about the Green Lantern.