No offence BFH, but that made me want to roll 2D20 and see what I get on a hit chart. It's too much like D&D. The stats I don't think that would be benificial to the game. However, your idea of giving bonuses/penalties have some merits. Your idea on lvling is basically the same thing as it is now, just a bit more drawn out. The whole idea of non human characters I love, but does not fit into the style of the game. The whole idea of Diablo is mankind(not the wrestler) saving the world from "evil" unhuman beings. Thowing different character races would blur this point. However, I do wish they had gender for some characters. The Paladin, and Barbarian must be Male, but a sorc could have a male counter of a Mage. Have a javalin Amazon, and a male Rouge counter. The assassin I can only see as a female character, but a Druid could be both sexes, as well as the Necromancer IMO of course.
My big issue with Diablo2 is that the whole game in general has been tainted with these runewords, and leet gear. To me I think it kind of ruins the game, no one wants magical items, or rares. Bring D3 back to it's primal nature, of use what you can find, and trade to defeat evil. No more of this Runeword stuff. I admitt, runewords, I got a bunch of them, but, without them, you are nothing in the game. That is my problem. You have to have them now just to keep up.
As stated previously, I would also love a "darker" D3. Maybe something like being on the brink of loosing to evil, no more daylight, and tons of new, and old monsters, but more of a mass at a time. I would like to see something of a better game structure, like not being able to kill players in a game unless somehow stated. Maybe have a preset when creting a game to toggle on/off character killing. Also a more of an interactive inviornment. Maybe have things that can be opened more, able to go up and down areas, ect. I have an image in my head of a battle that takes place on top of a tower, but you need to go up a circular stair case to get their, or maybe a wooden bridge that, is suspended between two trees high in the air. That when you step forward, it shakes, and makes waves. Maybe even rolling fog in the foreground would be nice. But these are just my thoughts.
As of skills, I would like to see a standard male/female character with some minor preset skills, but, can use scrolls, to use major skills instead of a "skill tree" That can be found, and/or bought from merchants. This IMO, would clear up the cookie cutter build argument. Gear could have both positive and negative effects depending on weight, type, strength to use it ect. I don't know, guess we have to wait and see if/and when Diablo 3 ever comes out.
EDIT: as an afterthought, maybe their could be a act where you could go to another plain to fight a boss character, and depending on what skills and character you use, you could become an elf, minitor, ect. That would please everyone a bit, because you could have you standard human, that become non humans.
d2 was just well..bah..fun but not scary