ESPN's Chris Mortensen is reporting that the two sides are closing in on an agreement which would bring the real officials back in time for Sunday's games.
Peter King says that if an agreement is reached by tomorrow afternoon, then the regular refs would indeed be available to report for work on Sunday. This is apparently thanks in large part to the work of Ed Hochuli, who has taken the initiative of keeping his colleagues up to snuff on the latest rule changes and testing their knowledge weekly.
Jason Cole says negotiations could stretch into next week, and the "ratification bonus" the refs would reportedly receive is compensation for the three weeks they've missed so far.
If a new deal is reached soon enough, it's even possible the real refs will be working tomorrow night's Browns/Ravens game.
Apparently, the NFLRA is agreeing to help train new referees, but will not unionize them or help pay for their training. The 121 current members of the officiating union are also reportedly accepting a payout in return for
selling out future refs concessions regarding their pensions. (Just kidding - obviously, both sides were going to have to give up something to come to a solution.)
Updated 2:34pm ET