Hmm... That Lunatic difficulty is just vague enough to make me think it could be a big let down. Traditionally their idea of harder difficulty has been more enemies in the same places, stronger enemies in the same places, and less experience (which is offset by the fact that there are more enemies to get experience from). It hasn't, on the other hand, been adjusting enemy strategies to make you think about the mission in a new way--the most you typically get in this regard is rearranging enemy units a bit and adding a bandit who forces you to move toward treasure/villages more quickly.
I'd love to see Lunatic difficulty mean "hard because it makes you think", but I'm sort of afraid Hard will mean "more enemies" and Lunatic will mean "more enemies than that".
Just to give an example of what I'm thinking of, the difference between Eliwood and Hector's stories in FE7 is a good example of making you think about things differently. Adding flying units to enemy forces, placing aggressive bosses closer to you, and having some enemies charge before they're provoked come to mind. This is the sort of thing I'd like to see a Lunatic do.