Since the main members of the cast (Jim Parsons, Johnny Galecki, Kaley Cuoco, Simon Helberg and Kunal Nayyar ) all have expired contracts, they aren't required to show up for work during the negotiations. So, if things aren't in place, production won't begin as scheduled on July 30.
The last negotiation was in 2010, and things have changed since then. Different reps are involved and there will undoubtedly be a salary increase request. Some say that they the cast could see $1 million per episode, given the $3 billion expected to be generated by the show.
