Sonic is a third party title, actually, as well as Layton. And Lego is something in-between, I'd say.
Seriously, Batman on 3DS bombed. Unfortunately, the console in the West (not just UK) has the Nintendo audience, the Japanese core-like audience, it's starting having some of the children audience, but it lacks the Western core-like audience. That's where Iwata (or whoever will replace him) must work for the next gen handheld. As I already said elsewhere, I'm sure just having two analogues will help in this, but it won't be enough.