I think that the choice of Stoller and Segel is an odd one given their resumes, but they are outsiders to the world of The Muppets and the way things have been done with them recently, which means:
a) The movie will hopefully not rely on its soundtrack to be "funky, zany, and a 'wild ride'". See "Muppets From Space". And,
b) The movie will rely less on having a "hot" (in the pop culture sense) human character driving the story, and the story won't suffer as a consequence. The Muppets will get to be the central characters. See "Muppet Wizard of Oz".
Bryan Singer allegedly had written a script for "The Next Muppet Movie", according to a story from some years ago. He would have made a great choice too, it seems the timing just didn't work out. While I wholeheartedly would much rather see a new movie written by Jim Lewis and Kirk Thatcher (with much love to Jerry Juhl), I'll take this over the alternative. No one's going to match Jim's original vision and genius when it comes to his characters, and to expect that is to set yourself up for disappointment. Still, I'm very optimistic that, if and when it gets made, we'll get a movie here that we'll all love.