Oh, and Monster Hunter. Let's not forget that. Very important!
Perhaps the most noticeable addition the new Nintendo 3DS brings to the table is a second thumb controller: the C-Stick. Two of the first games to take advantage of it are, of course, Super Smash Bros. for Nintendo 3DS and Monster Hunter 4G.
I the videos below, I quickly introduce the C-Stick controls for both games. Generally speaking, I like the C-Stick, and I've happy that Nintendo finally released a 3DS portable with it.
It's also worth noting that you can charge the Smash Attack by holding down the C-Stick. As with other C-Stick-based Smash Attacks, charging is simple, intuitive and effective. I'm very interested how Nintendo will use the C-Stick for future titles.
While using the C-Stick for camera controls, I kept instinctively comparing it to the sensation you get from using a standard controller's thumbstick—especially the way you can move the stick around. I don't think that's entirely fair, because there are certain built-in restrictions with portable 3DS hardware. So far, this seems like a workable solution. Time will tell if that's true.