Okay, here's some specific points as to why I could possibly see Daria and Butthead together in the (post-show) future...
1) According to one of the mail responses I got, B+B invite Daria to watch tv with them at the end of her first episode. Interesting enough beginning.
2) Daria will talk to them. Or at least Butthead (Beavis never says much to her, so...). Note from "Babes R Us" and the beginning of "Sporting Goods" and hell, throw in "Citizen Butthead" too, where she's apologizing for them (!).
3) A single line from "Sporting Goods": "Even smaller than I thought!" She was wondering about that part of them to begin with?!?
Just a thought...