Nothing to be gained, everything to be lost by region locking.
The Wii-U is looking far and far less appealing the more I learn about it. NoA consistently refuses to localize the games I want. Instead the try to cater to the casuals with titles like Wii-U Fit, SiNG, and Nintendo Land. Then offer backhanded tokenism to what they think the core wants; Batman, ME3, and the like. I fell for the whole spiel once with Wii. Third party developers are on board, just look at Red Steel! Not this time, Ninty has to prove themselves to earn my gaming dollars now.
I've never done this since I had an NES at launch (yeah I'm a grumpy, old bastard) but maybe it's time to jump ship to Sony. At least they want my money, even if it is in spades.