The Official Nintendo Magazine of the UK had a very in-depth feature on Metroid: Other M in the most recent issue (I think they played it in its entirety so it's basically a review, though no score was given). In short, the writer said...
The Good
The agility of the character and its contribution to the pacing: above everything else, this aspect of the game garnered the most praise. They say that Samus scales the environment smoothly at a blistering pace, with the basic controls being streamlined to make this movement easy.
The Metroid staples: apparently, despite the lack of coverage on this stuff, the staple elements of the franchise are still all there. The enormous areas to explore, the nook and cranny upgrade hunting, the exhilarating bosses - all present and all up to high standard.
The Team Ninja influence: aside from the faster pacing, which is likely one of their touches as well. The writer gave props to the melee combat and the dodge mechanic.
The narrative exposition: would you believe it, they actually enjoyed the story, especially the grand cinematic scenes that helped to tell it. Who would have thought, eh?
The Middle Ground
The soundtrack: not bad, but not great. It is supposedly a minimalistic soundtrack, driven more on ambience, and some extended sequences are silent.
The auto-targeting: mostly good, they say -- however, in cases of shooting into the screen or directly above the character, it was not completely reliable.
The voice acting: to put this bluntly, they called the voice acting decent, although the dialogue is 'sometimes a bit hammy'.
The Bad
The perspective transition: the writer mentioned that switching from 3rd to 1st person can be disorientating and takes a second or two to adjust, which may give time for the enemy to cause damage.
The new method of healing: unlike in previous games where you collect energy pellets to regain health, Other M asks to you to hold the Remote vertically and hold A to gradually regenerate. I'll leave it at that; you can probably guess why that would be a problem.
I really have to try this game for myself. As extensive as the article in the magazine was, it still didn't give closure for me. So yeah, got to find out for myself.