I expect that eventually Panda will become more dynamic. Since it's now a third essential leg of the ranking algorithm (relevance+connectedness+quality) having it only update manually every few weeks or worse doesn't sound like a Google-style long term solution to me.
The only areas of the algo that update slowly, as far as I can see, are things like automated taxonomy generation and n-gram identification. Those areas do not need rolling updates because they are global characteristics of the entire web and those don't change in a fast sweeping fashion.
So what we're seeing in some cases are reports that new pages on a Pandalyzed website can sometimes rank well, even though established pages stay demoted. I'm not sure if that means a rolling update, or just a less oppressive application of the Panda score.