The Muppet Show was my favorite TV show as a young child and would be a must buy theme for me! So many great characters, catchy music and humor.
As far as toys go you could have a Gonzo Cannon, Kermit's swamp lower playfield, Electric Mayhem pop pop bumper cluster, a mode where Fozzie tells bad jokes and you need to knock him off the stage, Pigs in Space, etc. It really has to be one of the best themes available at this point in time that hits a peak buyer demographic.