Romney cannot have a VP nominee that will upstage him, nor a speaker at the convention that will be better that he is. That leaves precious few speakers left to speak or to run.
They will also not allow conservative speakers as a matter of principle, except in backwater time slots that are scheduled to conflict with other important events.
I think Romney will pick Dan Quayle...
Personally I think Rick Snyder is on the short list.
He’s been under the radar and they can pass off his fiscal record as conservatism however those of us in Michigan know better. His fiscal record is purely by proxy.