Hmmm... I have played for only 10 minutes but the real only thing I noticed is that pretty much all skills (I beleive) get bonus's from other skills like the Druid's Wolves and Bears used to get.
Oh, and, the barbarian's WhirlWind DOES have a new animation like it was supposed to.
And lastly, you know thoes armors that are a blue tint in your inventory when they have like +50 mana? Well, the picture of the armor your wearing on-screen now is completly blue.
Hybrid Mode
