The agreement creates a way to speed up the process for limiting debate, or invoking cloture, once the bill comes to the floor.
Basically neuters Republicans.
Invoking cloture is still always available though.
The effect I see from it is that people will have fewer opportunities to invoke cloture- yet they will always have a chance to do it on any bill.
From the link above:
“... the package falls far short of what a group of more liberal Democratic senators had sought, it should accomplish one of Reid’s stated goals: allowing business to progress more quickly. In no case, however, will senators lose the right to force a 60 vote supermajority vote on bills and nominations as provided under the existing rules.”