Well, after giving the starter version a go, I have to say: it's pretty good. Normal lacks any sort of challenge for anyone who has any experience with the genre, but I knew that going in.
Honestly, I feel that D3 does a better job with the atmosphere (so far) than D2 did, although still not as good as D1. I don't get any complaints about the color palette, it looks fine. And the big, glowing blue crater in the cathedral levels looked really cool, I think. Graphics in general are decent and there are some nice effects, although I think the player characters could have used a few extra ploys and better textures, but eh.
So far, I'm greatly enjoying the Wizard and, to my surprise, the Witch Doctor. Contrary to a previous poster, I love Corpse Spiders.
I'm still iffy on the story, though. So far, it's not terribly interesting, and it looks like they're not only retconning [spoiler:7f4fa1fbbf]the D1 Warrior/Dark Wanderer into King Leoric's son, but if I'm not misinterpreting, it seems he had some sort of relationship with Adria, the witch from D1, and Leah is their offspring.[/spoiler:7f4fa1fbbf] I find it unlikely they're going anywhere but over-the-top, eye-roll inducing "epic destineez!" bullshit with that sort of retconning.