Hearthstone

I like the idea of a Warcraft CCG, but I haven't looked too deeply into this game. I tend to prefer Magic's complexity and flexible mana system to the simpler rules and "free or guaranteed mana every turn" systems that a lot of recent games like Scrolls, Kaijudo, etc have employed, though. Is Hearthstone simple to the point where the depth isn't there, or is it just easier to learn?

Easier to learn. There's still depth, not the level of M:tG, of course.
As said earlier, watch trump play, he's streaming now: http://www.twitch.tv/trumpsc
There's a 'low' amount of cards at the moment, obviously. So relatively the amount of different strategies and decks isn't as varied as M:tG yet.