Just because it shines doesn't make it gold.
No doubt, on talent alone, there are few (if ANY) WR in the NFL on Moss' level. Yes, the potential of Moss, Marshall and Bess would be high and offensively they'd have potential to be one of the most explosive teams in the AFC. Also, the Dolphins could get him for peanuts for the rest of the season.
HOWEVER, there's way too many red flags for my liking here.
With a young team, specifically on offense, do you really want Randy Moss in town potentially destroying the chemistry? The guy has openly admitted to playing "only when he wants to" and some of his efforts this season were outright embarrassing and you could tell he barely tried. On top of things, have you seen some of his antics this season? The embarrassing press conference he held while still in New England where he held a 15 minute rant about the organization and puffed himself? How about the one after the Viking game this weekend where he threw the entire organization under the bus? Do you really want him doing that crap here?
Two, sorry but when you're preparing to play on your third team in less than ten weeks, that's a huge red flag. You cut ties on a player that you picked up off the waiver wire for pennies to the dollar just a month after acquiring him, not a guy you gave up a draft pick in the first three rounds to acquire. There's a valid reason Minnesota decided to cut ties, and it sure wasn't solely because Brad Childress is a fool.
Three, he's a free agent to be at the end of the season, is going to command top dollar and is likely to call his own shots. It's very possible you could see him re-up in Miami, but again as I asked with Vincent Jackson-- do you really want to see this team invest two big contracts into the WR position?
I'm all in favor of improving the team, putting them in a better chance to win. However, there are far more variables to include in discussions when it comes to adding a player outside of talent alone, and Moss has way too many working against him for me to really feel comfortable signing him. Make no bones, if they do, I'll root for the guy and hope for the best, however I will be braced for the worst.
My opinion however is this may all be a moot point, as I see the Rams and Seahawks (both who have higher waive claim priority over the Dolphins) snatching him before Miami even has a chance. I also see the Redskins putting in a claim for him.