New Muppets attractions have been stymied by the lack of quality Muppets shows / movies. Muppets Wizard of Oz was supposed to be the big reintroduction of the characters, but it failed. Heck, even I didn't bother to watch it.
The new Muppet movie being planned by Jason Segel (Marshall from "How I Met Your Mother") is the next big thing on the horizon, so I'm guessing these attraction ideas were sparked by that project. Expect the ideas to be scuttled if the movie tanks, though (D ick Tracy's Crimestoppers, anyone?).
I like the Segel / Apatow brand of humor. It's more edgy and adult (like the original Muppets were in the 70s), so it could reinvigorate the franchise for a generation who thinks they are just cousins to the Sesame Street characters.