Actor Vin Diesel announced on his facebook page that Fast and Furious 7 will start filming this Summer:

Fast and Furious 7 Trailer

“There was an early screening in Los Angeles this week of Fast and Furious 6. The crowd reaction was surreal! and their demand for the continuation was powerful!
It’s remarkable to think I first embodied this character in 1999… and the evolution continues.

P.s. Filming of [Fast and Furious 7] begins this summer in LA, where it all started… talk about a studio in sync with the audience.”

Director

According to the online rumor, Fast and Furious 7 will pit Dom (played by Vin Diesel) against a new villain played by Jason Statham. The villain would be Owen Shaw (the main villain in FF6)’s brother and would be determined to avenge Owen.

If shooting on Fast & Furious 7 is set for this summer then we may hope for a release in 2014.
:)