Diablo III - Reaper of Souls - Information Round-up

[Frag]

You'll also be able to use a new NPC to re-roll a single affix on legendary or rare item. The 8 minute or so Loot 2.0 video covers a lot of it. Oh and Paragon perks apply account wide, though I stopped playing before Paragon stuff was in the game so I'm not sure how big a deal that is.

Paragon levels aren't a big deal to start with, but they add up quickly. You gain the same stats as you would have leveling up (3/4 to primary stat, 2 to Vitality, 1 to others) as well as 3% bonus magic find and gold find. The interesting part is I think that all of that is going away, and you'll be able to pick what you want instead, so you'll be able to customize your characters stats, like in previous editions.

To expand upon Smart Drops from the Loot 2.0 keynote, the amount of drops you see is (from their numbers) going down by a large amount. A full clear of A3 MP4 Inferno had these stats:

Common dropped now: 256
Common dropped RoS: 73 (28.5%)
Magic dropped now: 399
Magic dropped RoS: 266 (67%)
Rare dropped now: 275
Rare dropped RoS: 83 (30.2%)
Legendary dropped now: 1
Legendary dropped RoS: 6 (600%)

The real change is behind those numbers though, every rare and legendary has a chance to be a 'smart drop', which means it will be tailored with stats to suit your character and have a percentage to be a sidegrade/upgrade. In addition to this, the first time you kill a boss, you will be rewarded with a legendary for your class. As all legendaries can now drop as any level, this means you have a decent shot of receiving an upgrade.

As Kevin pointed out, if you receive an item (such as a dex based weapon) on your Wizard, you can swap the dex for another stat, possibly int.