see, the only thing i think people might have an issue with here is if they thought the rewrites were some kind of criticism of the original; if the challenge is to take a piece and rewrite it in your own style, or use it in a different way to make something new (such as those poetic-letter thingies), then it surely could not be construed as insulting.
*shrugs*
all people have to do is say they'd prefer their own material wasn't used, and don't even have to give reasons. that way, anyone taking on the challenge knows from the off not to use that person's poetry. seempuls!
Yeah, you could go at it like an editor, but I'm thinking more of a radical re-write. An exercise in creative plagiarism, or as the oldies used to say, "In the style of..."
We'll get a list of people who'll let us use their poems, if this challenge were to exist.