I agree with Prawnie and Beaker, most definitely. Why would you want to change up who we've got? The performers are fantastic. So what if you know someone who can do a Kermit voice closer than Steve can. Can they do the personality? Connect with the other characters? That's a whole other thing entirely. Steve is awesome, 100% I don't care what anyone says.
To whoever suggested bringing Frank Oz back, I disagree with that too. Why want someone who obviously wants nothing to do with the muppets? That's fine, he put in his time, he wants to leave it be, he has the right to do so. New enthusiastic people, and the veteran dedicated hard workers is what this film needs, and it seems like what it will be getting, and for that I am pleased.