SPECULATION ALERT- I wonder if they're goal (assuming the new character is the personification of the Master Sword) is to make it so that you have to find a way to make "her" become the sword again. I don't see how Link can strike down evil with a sword that isn't a sword. That'd actually be a wicked plot by a villain if they turned the sword into a person so it couldn't be wielded as a weapon against them. Of course then Link might come to have an emotional bond to this new character, then cry manly tears when he has to revert her back into a sword to defeat the bad guy, who I'd assume is Ganon. To think a single image can spark so much speculation and brain storming...

A Metroid game with less puzzles and backtracking means less exploring and thinking, which in turn makes it less like a Metroid game and more like some some generic shooter.

Tallon Overworld? And I doubt you'll enjoy Other M if you couldn't beat Prime 1. Team Ninja is known for difficulty in their games. I think its likely that Other M will be a harder game to beat than the Prime series if Team Ninja was given the freedom to actually make the game as hard as they pleased.

I think it's a younger Samus. She is seen speaking with Adam when he is alive, right? She'd have to be younger and possibly look different. Judging from the trailer: seeing Adam alive, seeing Mother Brain blasting the baby metroid, and enemies that look awfully Fusion-esque I think the game will cover more than a single time period. It may jump forwards and backwards with gameplay and/or cutscenes to fill in Samus' backstory better. If so, I'm all for it.