I am not sure if disney plans on using clips in the roast or not, but if they do then i hope that they use some clips from The Jim henson Hour and Muppets Tonight.
I wonder who will roast kermit: celebrities, muppets, or both. It would be cool if the newsman and/ or Fleet Scribbler did a report on the roast at the beginning (like how kermit did a report on Elmopalooza at the beginning of that special).
As fo Sesame Street characters being needed for Kermit, think of this: even when henon owned part of the rights to the sesame Street characters, Kermit wasn't normally seen as part of the gang. In follow that bird and most of the specials, he normally appeared as a news reporter. kermit rarely appeared in any Sesame Street cast photos (although I have seen a cast photo from the first season with him). He rarely appeared in illustrated Sesame Street books. he rarely appeared as part of the Sesame Street gang (did he attend Maria and Luis' wedding? did he go to the metropolitan museum of art with the cast? did he appear in Big Bird In China? did he go skating with them at the beginning of Christmas Eve On Sesame Street? was he in The Muppet Alphabet Album?).
Also, he normally appeared by himself on sesame street, or with one-shot anything muppets. he normally appeared with grover, and there are quite a few sketches where he appeared with the Count, Cookie Monster, Don Music, and Dr. Nobel Price, but he pretty much stayed away from the regular cast on a regular basis. You might have noticed that whenever sesame Street characters cross over with the muppets, they rarely interact with kermit anyway (kermit didn't talk to any sesame street characters in A Muppet family Christmas, and he hardly talked to Big Bird in the leslie uggums episode of The Muppet Show).