Class systems have a bad habit of getting in the way during a role-play anyway. I understand why people sometimes need them in an MMORPG in order to create a semblance of structure to the game's system, but I think a more fleshed out system like this works more ideally for a piece of writing. Honestly, I don't particularly like class systems at all -- it makes more sense to have the characters be proficient at whatever they choose to master, rather than just say 'oh, you use a sword -- you're a knight then and you can't possibly use magic'.

The Elder Scrolls is a good example of what he's doing here, yeah -- too bad that franchise's MMORPG didn't follow suit.