The Edge going to Miami isn't possible this season. The Dolphins don't have and can't afford to make a trade this season. I bet the Colts wouldn't mind getting some draft picks along with some veteran help in the D for the Edge since they pretty much have a back to fill in Edge's void.
The Colts aren't sweating Edge...next year the Edge and Harrison are free agents and they'll only be able to bring Harrison back and have Dominic Rhodes as starter in the RB position. It's in the phins best interest to just hold out this season to get thier back without sacrificing much. The Bills waited a season for their back in McGahee...the phins can do the same with Edge. It'll be a pleasant move for both since Edge wants to move back home and the phins are in desperate need for an established back with size and skills.