Back when Screen Rant chatted with Vin Diesel on the set of Fast Five, the brawny actor briefly discussed how that film was being fashioned to serve as the middle chapter in a trilogy - with Fast and Furious 6 bringing the tale of Dominic Toretto (Diesel), Brian O'Conner (Paul Walker), and their fellow professional criminal/car racer types to a conclusion of sorts.
Rumors popped up in Fall 2011 that not only was Fast and Furious 7 also on the way, but that the sixth and seventh installments in the high-octane thrills franchise could shoot back-to-back and feature the addition of Jason Statham to a cast that already includes macho leading men like Diesel and Dwayne "The Rock" Johnson.
The Statham rumors are (officially) just hot air right now; similarly, there's been no confirmation about the possibility of the Fast Five sequels being filmed together. However, new comments from Diesel do reveal that Fast and Furious 7 is being actively developed - in fact, Chris Morgan (who penned the last three chapters in the franchise) has begun scripting both the sixth and seventh movies, according to the actor.
Here is what Diesel told THR, with regards to how the planned (second) Fast and Furious trilogy evolved into a quadrilogy:
“With the success of ['Fast Five'], and the inclusion of so many characters, and the broadening of scope, when we were sitting down to figure out what would fit into the real estate of number six, we didn’t have enough space... We have to pay off this story, we have to service all of these character relationships, and when we started mapping all that out it just went beyond 110 pages. The studio said, ‘You can’t fit all that story in one damn movie!’"
Universal is (certainly) also anxious to keep this particular cash cow alive and well, especially if Fast and Furious 6 proves to be a box office smash - which it almost unquestionably will be. Thus, having a seventh installment written and ready to go before cameras quickly (assuming it isn't simply shot simultaneously with Part 6) is something the studio would definitely approve of, regardless of any potential plot contrivances needed to make it happen.
That said: Diesel does have a point about Fast Five vastly expanding the "scope" and number of character-based subplots in the series, so a seventh chapter doesn't (per se) require a huge stretch.
Fast Five left the door open for Johnson's relentless federal agent Luke Hobbs to continue his pursuit of Dominic and Co. in Fast and Furious 6; by all accounts, the semi-antagonist will be brought back for the sixquel (?), which has long been expected to take place in Europe - a possibility also set up directly by Fast Five's mid-credits scene - and see the return of certain characters from previous installments in the series.
Universal chairman Adam Fogelson has likewise suggested that Fast and Furious 6 (and, by default, Part 7) will also continue the trend established in Fast Five - by moving the series closer to the classic heist/caper genre, while still incorporating the hyper-kinetic chase sequences that the franchise is so well-liked for.
Fast and Furious 6 is slated to hit U.S. theaters on May 24th, 2013, so expect to hear more about both that film and Fast and Furious 7 over the upcoming months.