I've been scratching my head about this as well. From what I can tell, the Repugs got everything in this compromise, including a pledge that the Dems won't filibuster except in "extraordinary circumstances." But there's nothing to stop the Repugs from going nuclear then either.
I also read something the other night that said that the rules change threatened by the Repugs actually included a circumvention of the usual rules to change a rule. That is, in order to change the rule, they wouldn't obey the normal rules, which require 60 votes. But they were somehow going to use Cheney to circumvent this. How? Does anyone know?
Christian