Yes, Miyamoto warned us about the camera system, and it's troublesome.
I can't help but feel a little disappointed with Super Mario 3DS. It's really cool to have the Super Mario Bros. 3 environments and power-ups return. However, the re-introduction of the Super Mario 64-style camera is a big downer for me. The camera doesn't move optimally when viewing with 3D off, making for deadly jumps (sunlight during the demo made it hard to use 3D). Though it looks a lot like a Super Mario Galaxy game, it sure doesn't control like one. The circle pad feels cumbersome, and the focus on smaller platforms exacerbates the issue.
The leaf and tanooki suit have combined into one power, which feels kind of like a Yoshi suit with the way Mario floats down. The addition of some Super Mario Galaxy elements to the Super Mario Bros. 3 environment isn't groundbreaking, but it's a nice combination. A side-scrolling airship and even Boom-Boom returns.
Those are my thoughts. For more details of the actual game elements, I suggest reading Neal's impressions.