Recently when CBS and Warner Bros. TV inked a 3 year pick-up deal of over $4 million per episode, it was cast contingent. The problem is that the show starts filming it's 8th season on July 30th and at the moment, stars Jim Parsons, Johnny Galecki, Kaley Cuoco, Simon Helberg and Kunal Nayyar do not have contracts for the new season. Only Melissa Rauch and Mayim Bialik have deals after renegotiating their contracts last fall.
According to Deadline.com, the series is expected to make more than $3 billion for Warner Bros TV. Under their previous contracts, Parsons Galecki and Cuoco were making $350,000 per episode for season 7 plus owning 0.25 points on the back end. With the new deal with CBS, it's expected that the three main stars can negotiate around $1 million an episode and a bigger back end cut with a new contract.
If filming is delayed because of contract negotiations, even if as long as until Labor Day, the show is still expected to be able and produce an hour long season premiere for September 22nd.