It would be cool to have a "successor system", but since it's against the lore, we won't have anything like this. [We've talked about it a lot a while ago.] Perhaps some decent coder will be able to mod in a successor system.

I would be up for something like that, one of my favorite games is Crusader Kings (because of the dynasty system).

I didn't mean to turn this into yet another thread about it because I wasn't really asking for a true succession system, just the ability to manually retire your sovereign and designate a son or something to become one. Even though I'm sure I'll like the traditional version of the dynasty system within the game, an actual succession mod would be awesome as well (the one you guys are talking about).