Using melee weapons has always been decent. Using Magic has always been interesting, but both of those can always be expanded on. So that leaves stealth. I REALLY didn't like Stealth in Morrowind, in Oblivion it was a great improvement, but it was still lacking. Honestly, I kind of consider the bow part of Stealth, even though it is kind of a combat thing. It would be nice to see certain enemies break the arrow's tip off once it's inside of them. Then other enemies limp or whatever, because they have an arrow in them lol. Which would depend on strength and/or agility, or something like that. Just my thought.

I voted Magic.

Fighting was very base, but much better than Morrowinds "Always use best attack" type of fighting.

Magic wasn't done bad. But it's Damage output and use in stressful, on-the-spot situations was lacking.

Stealth was pretty great in my opinion.

I personally wouldn't be too disappointed if they kept it as it was. Perhaps tweaking NPC AI would help exploiting it... but the "seen and unseen" marker was excellent to me.