I'm not sure exactly how the parliamentary rules of the Senate work, so I'm not sure if this would be feasible. But maybe both parties could agree to phase out the filibuster at some point in the distant future. For example, maybe they could agree that at the start of the congressional session in 2017, it would be eliminated. That's far enough into the future that neither party would have any idea who would initially benefit from it, and could therefore vote to eliminate the filibuster. It would eliminate a destructive force on our legislative body, without anyone needing to vote to maintain the filibuster to protect their short-term political interests.