As well as the above still, EW also have some new plot details. According to them, the sequel will find our heroes
"enjoying a triumphant world tour, only to become tangled up with a criminal mastermind named Constantine, who is out to steal an enormous diamond—and who happens to be a dead ringer for Kermit". The site also confirms that Ricky Gervais will play a baddie (Constantine’s villainous sidekick), and Tina Fey a "Russian prison guard". Ty Burrell is also on board as an Interpol agent.
The Muppets...Again! is currently shooting in London with a March 21, 2014 release date. For an interview with Kermit himself, click the link back to EW below.