http://wii.ign.com/articles/107/1071925p1.html <-- spoilers within, so here's the interesting bits:
-- 2D controls are D-pad to move (tap any direction to do a sidestep), 2 to jump, 1 to shoot, and A for the Morph Ball. You can drop normal bombs in the ball with 1 or hold the button to rev up a Power Bomb, and you can do the scatter-bomb ability from Fusion by holding a charge shot and ducking into the ball. (The functions of + and - aren't known yet.) As usual she has the Wall Jump, and it sounds like it's done in the same fashion as Super.
-- In first person mode, you cannot move; only attack (A), look/lock-on (B) and presumably scan. As previously explained you get in and out of FPS mode by pointing the remote at the screen.
-- There seems to be an auto-aiming effect in place where if an enemy is near, Samus automatically points at it when you shoot. Regarding the cinematic attacks:
you can also play defensively. When enemies shoot projectiles, you can cinematically dive out of harm's way if you tap any direction on the D-Pad just before impact. Works flawlessly and looks good, too. Time it just right and Samus can pull off reversals on alien attacks, too. And if you beat an enemy into submission, you can also perform a thrilling finishing move complete with a sweeping camera that spotlights Samus as she cinematically disposes of the poor creature in question.
-- In cutscenes Samus does most of her talking via monologues. BTW, Remember Me Black Guy is now known as Anthony Higgs - same initials as Armstrong Houston, anyway.
-- They claim this about exploration:
The design of the world -- stretching in every direction, separated by doorways (some of which are locked), multi-tiered -- facilitates exploration, which was a previous point of skepticism for me. Nintendo reps on hand said that the demo only represents the very beginning of the game -- by comparison, the first 45 minutes of Metroid Prime, at which time exploration has only just begun.
Dunno why I didn't think of that, quite frequently the start of a Metroid game is the point with the least amount of room to wander.