The skill/rune system (does it even have a name?) is really more like the skill-based system in UO or even EVE online than it is a classical RPG where you just level up, get arbitrary points, and invest in a new talent.
I've honestly never been a fan of the classical system. Talk about "casual". All the characters are basically the same, save for a few stats points here and there. One of my favorite things about UO was that you could specialized in anything, to any degree you wanted. I also like how all skills are useful at higher levels if you develop them. In D2 if you put 10 points into a low level skill it was probably still going to be a garbage build.
Honestly, I wish they'd just get rid of "levels" all together and increase your skills based on usage.
Worth a read: http://us.battle.net/d3/en/blog/4475014

