Oh, they better do it, I NEED Metroid 5. The way Fusion ended created very interesting possibilities for the sequel, story-wise. But I'm afraid of the art style they might use... 2D games on a 3D graphic can look pretty weird at times.
And I have mixed feelings about a Metroid 2 remake. On one hand, I'd absolutely love it. On the other, there is a fan working pretty hard for quite some time now and it'd be pretty bad if all his work went for nothing. It's called AM2R, and it looks oh so sweet.