Apparently, it would have been a straight-up, player-for-player trade. That sort of trade is very uncommon, with the last high-profile one (AKA last one I can remember) back when the Broncos and Redskins swapped Champ Bailey and Clinton Portis a few years back.
The only question now is why in the world would the Dolphins trade away their best player for a wide receiver?
Don't get me wrong, I think Edwards is a good wide receiver and will really explode in New York, but it just doesn't make sense for a running team to trade away their best running back for a wide receiver that would not touch the ball all that often.
The Dolphins must have figured that another target for the heir-apparent Chad Henne would not be a bad thing, and Ricky Williams as your starting running back isn't exactly a terrible plan either. Add Patrick Cobbs, a young, emerging player, and you have a pretty good backfield for the season.
I'm sure the Browns were crossing their fingers hoping that, for whatever reason, Bill Parcells would bite on this, because although Edwards is a good player, he doesn't have nearly the impact or versatility of Ronnie Brown.
Plus, Brown playing for the Browns? That's just too much.