I see how this could be scary, but it could also be worse. Labron has started to look like an Allen Iverson type player (albeit much larger, much better, and much scarier), but he needs the ball in his hands, and apart from being a good scorer, he doesn't run a great offense. He is predictable and his decion making is his weak point. Now, that doesn't at all mean he's not scary, or that pairing him up with a Bosh is not scary, but it just means that the combo will not be any greater than the sum of the pieces. I think pairing Bosh with Wade, who knows how to play with other players and get them involved (ie winning a ship with Shaq), and works in a team oriented offense (it focuses on him, but it isn't strictly him as much as CLE is Labron) would be scarier. I woul take my chances against that CLE team than that Miami team.
(I also think the Wade/Bash/beaches will attract more FAs than the Labron/Bosh/CLE combo)