Yes! Dean gives endlessly of himself, body and—quite literally—soul. I think you're right to highlight the cessation of that as another essential part of him attaining maturity. Wouldn't it be amazing to see Dean actually gain some sense of self-worth, of himself as important in a manner that goes beyond simply being another tool to be used, another thing he can sacrifice?

I think the ring itself might be significant. That we might see them collecting objects of power from each of the horsemen, and using those in some way. I like this idea because it's got that old-fashioned questy element to it, and I love me some quests.

Also, you know Dean could always use some more bling, so. *g*