How much sex, violence, and profanity are in this movie?
For detailed information about the amounts and types of (a) sex and nudity, (b) violence and gore, (c) profanity, (d) alcohol, drugs, and smoking, and (e) frightening and intense scenes in this movie, consult the IMDb Parents Guide for this movie. The Parents Guide for The Muppets can be found here.
From Entertainment Weekly: "Walter is a sweet, slightly naive twenty-something Everypuppet who, in the movie, is the brother and roommate of [Jason] Segel's character, Gary. Both Gary and Walter are die-hard Muppet fans. 'Walter is the kind of guy who faints when he sees Kermit,' [James] Bobin says. Of course, Walter's Muppet fandom is complicated by the fact that he is a Muppet himself. 'Walter has a bit of a self-confidence issue because he's the only person like him that he's seen aside from the Muppets,' Segel explains. 'His dream is to meet the Muppets and be around people who are like him.'" Walter will be puppeteered and voiced by Muppet performer Peter Linz. Rumors of Michael Cera or Paul Rudd providing the voice are incorrect and are based on a misinterpretation of an idea in the script.
Will this movie be done with classic puppets or CGI?
Classic puppets. According to most sources, the script contains very few shots that will require the use of CGI. They will still be using computer technology to remove arm rods, etc., as they have since at least Muppet Treasure Island.