So I've been playing Skyward Sword for the past two days, for five hours each (shame on me). Here's what I have to say so far:
1) It is VERY easy to fatally screw up. Just about every enemy gives out one heart of damage. In just one case, I have had one quarter of a heart taken from me.
It kind of reminds me of the original Zelda, where you could get 16 hearts total (which, apparently, is the same amount of max life in Skyward Sword), and each enemy gives out 1/2 to 2 hearts damage. Speaking of which, I am really enjoying the difficulty of the game. I have had numerous accounts where I almost died, but was able to salvage myself by either a potion or using he beetle to find hearts.
2) The combat is great. So great, that I feel that there is not enough so far. This is made up with the amount of exploration required to progress, which is always accepted by me. Some of the latest titles have lacked that key element, and I was glad to see that again. Also, hearts are sometimes kept in little secret areas, such as the tops of ledges or underground, which also adds to the exploration.
3) The upgrade system is polished and feels rewarding. It always feel nice to collect your hard-earned items and having ability to make it into something great.
4) I may stand in a minority when I say this, but the music in the game is great, but lacks the catchiness of it's predecessors (with some exceptions).
5) lack of control of the camera. I know, the camera is positioned in a way that you can get all of the action, but I missed having complete control of the camera (a la Wind Waker), but that's just me. Maybe the combat would get awkward, idk.
So yeah. That's my opinion of the game so far. If you have never played a Zelda game before, this would be a great start. Buy this game, and you will not regret it.