According to the NHLPA official website, arbitration dates for Brandon Dubinsky, Ryan Callahan and Brian Boyle have been announced.
Brandon Dubinsky: July 21st
Brian Boyle: July 25th
Ryan Callahan: July 28th
So Glen Sather now has the timeline for getting all three under contract. It's unfortunate that the Rangers players are on the earlier side of the arbitration hearings, but it is what it is. Sather said after he signed Brad Richards that he expected to get all five players under contract in the near future. He took care of Artem Anisimov today and avoided arbitration with Mike Sauer today as well.
Now he will have to focus on Dubinsky, Boyle and Callahan. I would assume Sather expects to get all three under contract before arbitration, but obviously we don't know too much about that as of right now. We will have more information on the negotiations as information comes out.
But for now, the finish line is within sight.