I don't know. Manning to Harrison was an unstopable combo when Harrison was in his prime. Well, Edge had a lot to do with it to, the Triple Threat. The reasons why I think Beck to Ginn will never equal Manning to Harrison are as followed:
1. The offensive line
With Glenn protecting Manning's blind side and four other pro-bowl offensive lineman Manning had all day to throw. Miami's line isn't like that. In the limited action Beck saw last year he was scrambling a lot. That's not good when your talkin about putting up Peyton Manning like numbers.
2. Harrison (in his prime) is a better WR than Ted Ginn
Harrison in his prime was an unstopable WR. He knew how to never take a hit, which helped him stay healthy all throughout his career. His hands were money all the time, never see him drop a pass. Ginn, on the other hand, hasn't shown "money" hands yet, or the route running that Harrison had. Harrison's routes were so crisp, and Ginn still needs to work on that. Ginn will be a more valuable KR/PR, but as a WR Harrison is one of the best.
3. Edge
He was a very versitle back when he was with Indy and understood his role in the backfield. He could pound for the 3 and 1 play, and take a screen pass 25 yards for a first down. Not to mention, his play fake ability. Ronne has shown glimpses of being a better back than James ever was, but untill Ronnie can show me he can stay healthy 16 games and still be a top 10 back in the league, I have to give the nod to Edge.
4. The play-action
Line backers, DB's, even DL were all affected by Manning and James play fake. Arguably the best play action QB of all-time, Manning was able to freeze DB's on pass plays which opened up seams for Harrison, Wayne, and Stokely. And then when he'd give it to Edge, the DB's and LB's would be a step too slow becuase they would be worried about the pass. So Beck isn't there yet and probably never will be as good as Manning.