Disney seems to want to strike while the Muppets are hot. That's a good thing. This is an approximate breakdown of what is required for a Summer 2013 release:
- 3 months to complete & polish the script
- 3 months of preproduction, soundtrack, set building, location scouting etc.
- 3 months of production and filming
- 3 months of post-production editing, effects and mixing
It can be done and not be rushed if they hit all green lights without any substancial set-backs over the next year. Television is an entirely different creature than film so I wouldn't compare the rushed specials to this sequel. However, I suspect this will be a holiday 2013 release. Either way, this is great news!!