If the GOP wins the ones you listed, I am pretty sure that would win it. we might need one other state to get over the top. in 2004, Bush won with that list. I think Iowa went Red, too, if I recall correctly, but a combination of OH and FL with VA and NC should be enough in 2012. I suspect NH is a lock, and Iowa should be if the economy stays down.
So, if we held everything I proposed, we would still need one more state to get it done (or two more if one of them is New Hampshire +3).
Not a slam dunk, but certainly very doable as long as we have a reasonable candidate and there is not a strong third party candidate running.