Naner: Cutscenes can hamper a game just like any kind of ill-begotten ideas or investments can. Is the Metroid franchise apt to deliver the kind of cinematic experience Sakamoto is striving for? That is the question here. Remember that nothing comes free. The series might gain something, but what is Nintendo giving up to make that happen?
Anyway, for me, Metroid is not about 'Shooting Space Aliens' at all - it's about atmosphere. The sense of solitude, of wonder, of fear - that is where Metroid shines. The gameplay exists to makes that experience possible. So does the backstory. And yes, I consider the Metroid hatchling's sacrifice in Super Metroid to be a touching moment. The thing, however, is that it is just that - a moment. Super Metroid uses simple but powerfull techniques to tell its story through player exploration, atmosphere and action. The game is true, in that sense, to the 'essence' of the medium.
Will Other M have that kind of purity? Most likely not. And what of the sense of solitude? Will that be gone as well? You could point to Fusion and Metroid Prime 3, but three wrongs does not make one right (note: I really liked Fusion, though I fail to see the point of the mandatory exposition dumps). I believe it is too early to make any kind of solid judgment about the game yet, but I think I can safely say I would have been more at ease with a less cinematically oriented endeavor.