I think Twisted's refactoring was kind of like Zope 3's refactoring, which happened in theory previously but no one used it. Actually getting usable isolated packages out of Zope 3 was hard, just for technical reasons, but also because the people doing the work didn't have much incentive to deal with the issues like getting the tarballs pushed somewhere and whatnot. Now they are taking a different tack with Eggs, and I think the result is potentially useful where the previous one wasn't. I think entry points are also really important here, because it's an actual novel feature which makes packaging matter as more than just a way to deflect criticism.
I also think people will really use the new Zope refactoring, if it is done well -- especially extracting small things (like, say, the transaction manager) instead of trying to extract "optional" things like the ZMI. The transaction manager is useful on its own, the ZMI is not. Similarly, the things Twisted should extract are things like the Deferred stuff, not the optional pieces like the protocol handlers. Right now I think the lack of a solid idiom for async programming (barring the use of the entire Twisted stack, or ad hoc callbacks) really keeps people from using that kind of programming in places where it might make sense.