While I don't really think we'll see one, I'd love for it to happen all the same; I think the girls coming back together to talk about the great thing they did would be wonderful, but again - I'm just not too sure if it'll happen. At best we may end up with an 'E! True Hollywood Story'...if that.
Still, if it did happen, I'd love for them to have all the sisters in it (and Leo of course), not just Paige-Piper-and Phoebe...Prue (Shannen) should be there too; since it'd only be an hour long I'd like for them to do something like '90210' did where they crammed as much stuff into it as they could...talking about each character and then the actors themselves and all the behind the scenes memories, plus I think they'd have to do something with Constance M. Burge, after all, if it weren't for her we wouldn't even have a show to begin with. I'd be interesting for sure and I'd definitely watch, I'd just hope someone like TNT would run it instead of the CW...mostly because then I'd get to see it.
That way they wouldn't be treated horrible unlike certain networks did to them.