Mr and Mrs Smith

The NY Mag reports that Regency Enterprises,developing a quasi-prequel to the 2005 Brad Pitt–Angelina Jolie hit Mr. and Mrs. Smith without its original stars.

The new film, which will possibly be titled Mr. and Mrs. Jones, will serve as an origin story about a pair of twenty-something spies who are set up as a fake married couple when they graduate agency training.

Clearly there's an economic reason for this, as Pitt and Jolie don't come cheap, and Star Trek showed that fans will flock to an established franchise even without the majority of the original cast. Notwithstanding this, the original film coasted on it's stars charm and chemistry and questions remain about the viability of any sequel which doesn't feature them.