There's a bit of a long story about how the Walt Disney company wanted the talents of Jim Henson, and were willing to buy the Muppets just to get him. Unfortunately, he died before the deal was ever finalized, and the company lost interest in the property, and it was sold to a German company.
But Disney had a license to use the muppets in some situations, including as a part of Muppet Vision 3D at the studios. So that remained open, but couldn't be expanded beyond that.
Then, the German company went bankrupt, and Disney wound up acquiring them - at a fraction of the original price. But they had no idea what to do with them, and the Muppets mostly just sat idle.
And with park expansion, Muppet Vision finally closed. The Muppets will appear as a replacement for Rock'N'Rollercoaster, but that really doesn't do them justice.
In the meantime, the Disney company has been considering other ideas. One of them was a resurrection of the Muppet Show. They produced one episode and released it in January. It followed the formula of the original 70s era show - and I have to say that I enjoyed it.
There is some discussion of producing more episodes, and I sure hope that they do.... and don't just continue to let them languish and ultimately be forgotten.