I just don't understand the reasoning behind it. I'm worried it will just end up feeling unnecessary. Like I said, the swamp looked like a good use but the grate bit was needless. I'm also worried about the auto-aim dumbing down already simple combat. Enemies were mostly obstacles in the 2d games rather than duels and strategic fights like they had started to become in Prime. Auto-aim doesn't even make them an obstacle anymore. I assume auto aim is a quick fix to hitting enemies on a 2d plane in a somewhat 3d environment, but eh. And the grappling moves are just wrong.
The series needed its speed back, but I hope they don't fuck over the whole of the game along the way. I remember thinking with Prime, that even if it didn't end up a real Metroid game that it could be at least a nice FPS. With this, and the glutton of action games out there, I don't care if its just a good action game. Bring me Metroid.