In the wake of Fast Five’s box office success, the LA Times reports that Universal has writer Chris Morgan and director Justin Lin working on a sixth and seventh movie. The next two films would be connected by a single story and shot back-to-back to capitalize on the recent success.
This follows the increasingly popular Hollywood trend of filming two movies at once. Recently, the final two installments of The Matrix series as well as the second and third Pirates of the Carribean movies were filmed consecutively.
Peter Jackson famously filmed all of the LOTR trilogy over the course of one year and is currently filming both Hobbit movies at once, as is Cameron with his upcoming Avatar sequels, and it is rumored that the pending fourth and fifth Transformers movies will be shot likewise.
Presumably, Universal hopes to lock up the cast and crew by filming this way and to capitalize on the current public interest in the Furious franchise. They do seem to be running a risk by investing this much time and money at once, given the lack of interest in previous installments, but clearly they are not the only ones in Hollywood to be doing so.