While Christoph Waltz had been in negotiations to take the role, Modern Family's Ty Burrell has now secured the chief villain part in the next Muppet movie. According to The Hollywood Reporter Waltz is out and Burrell is in because a scheduling mismatch.
This means Burrell will be in two family films on release at the same time - this one, and Dreamworks' Peabody and Sherman in which he's playing the dog. In that case he inherited the role from Robert Downey Jr.
All other details remain the same - it's a caper, it takes place in Europe, we're still waiting to hear on other human cast members.
James Bobin is coming back to direct again, Bret McKenzie is writing the songs and the key roles of Kermit the Frog, Miss Piggy and Fozzie Bear have gone to Kermit the Frog, Miss Piggy and Fozzie Bear respectively.