So, if we're going to have dynasties, marriages, heirs, etc, will there be bastard children born out of wedlock? It might be interesting to use this idea as part of the quest system. If you take too many turns to rescue the princess or queen, she's pregnant when you finally do. Cheating spouses could have diplomatic consequences. Bastard heirs could be welcomed as a new and unexpected hero or could pose a threat to your kingdom, arriving with an army you'd have to deal with.
Just a few thoughts. I'd love to hear any ideas it stirs in anyone else.