Not only does Andy Dalton have experience in the spread and posses the tools to be a very dangerous passer in a shotgun formation, the Bengals have the personnel to spread teams out and create multiple mismatches on the same play.
If the Bengals bring Chad back (which they should) him and A.J. Green alone will open things up. Both receivers demand attention and it'll be very dangerous for defenses to leave them in single coverage. The Bengals can go with a lot of four WR sets because they are deep at the position so players won't get tired. On top of Green and hopefully Ochocinco, they'll have Jordan Shipley, Jerome Simpson, and Andre Cadlwell.
Don't forget about Jarmaine Gresham either. Imagine this formation: Dalton and Benson, Bernard Scott, or Brian Leonard in the backfield (depending on the situation), Ocho and Green out wide, with Shipley in a slot and Gresham lined up in the other slot close to the tackle.
Simpson and Caldwell could come in to give guys rest and mix things up. That would be a lot of receiving weapons on the field at once and what are the weaknesses of both the Steelers and Ravens defenses? You guessed it, man to man coverage.
The Bengals are all of a sudden pretty deep at the skill positions, they need to take advantage of that.