Looking at the skill/rune notes, it reminds me of looking at Crusader when it was coming out. Without seeing the legendary and set bonuses, everything looks kinda... soft, I guess. The Crusader was designed with set bonuses in mind and still isn't in as good shape as some of the older classes. Hopefully Necro will fair better. Right now, they're saying the 4 sets will focus on: Pets, Melee, Ranged caster, and "Blood focused", whatever the hell that means - I assume lots of health pool management as your resource.
Some of the runes look fun but like they probably won't be used ever unless the sets / legendaries are much better designed than the other ones so far. Honestly, the passives almost all looked really meh, even for passives.