I went to D23 09, and yes, I went to the Muppets panel. (I did not wait the incredible 2 hour wait afterward to personally meet Fozzie, Gonzo and... I can't remember the other Muppet at the moment) In retrospect, it was quite a disappointment. Except for merchandise, literally every single announcement never came true. I think the only one was the Bohemian Rhapsody, but it had already been produced (or was in the process of) when the panel was going on. They announced a Muppet theatrical movie that never got made (Cheapest), different music videos/parodies that never were produced, a Halloween special that was never filmed, Muppet Whatnot Workshops in CA and FL that were never built, an overhaul of Muppet*Vision 3D that never happened... and so much more. They also had one Muppet perform in person very briefly: Sam the Eagle. (yeah, I don't know either) There was some pre-filmed thing but it was over quickly. The studios presentation had way more Muppets, which was kinda weird. No mention of Jason Segel whatsoever either. And he had been connected with Disney/Muppets for over a year at this point.
I'm guessing the film took up most of the time, which let these projects fall to the wayside. I didn't go to D23 '11, but oddly I think there was less Muppets there.
As for the parks, aside from character meet and greets that will surely be revitalized in 2012, don't expect much. Imagineering is straying from the old 3D film attractions since the effect (which is the main factor in attracting audiences) can be viewed in movie theaters across the country. So don't expect MV3D to be updated, however it will get a new lease on life as the new movie should give the attraction a popularity boost for a little while. New attractions down the line? I can't say "never", but for now don't count on it. Think smaller, like the Muppets getting a segment in California Adventure's World of Color, or even a little daytime show. Their presence will be increased, but in tinier doses than you might imagine.
I think for now, Disney's main focus is finding other ways to utilize this now confirmed-to-be refreshed franchise.