So far I've only done one Cousland origin: male warrior (~points at avatar pic~). And in this one I chose to sacrifice myself. I do plan to play through DA:O as a nefarious male rouge Cousland that ends up being King, and a stern female warrior (shield) Cousland that becomes Queen. But both of them will have to wait awhile; I've still yet to do the Dalish Elf origin, and the two Dwarf origins. >_>
I do hope that my Marus (who sacrificed himself) will get some mention, assuming of course it's possible to carry-over his playthrough into DA:A and beyond. Maybe something like, "Oh, you're the new Warden? You got some big shoes to fill! The last one saved all of Ferelden he did!"
I think any storyline involving both Morrigan's child, and/or Alistair's own children, will likely happen in a proper--full--sequel that takes place a couple decades or so after DA:O. The storylines involving the continued Theiren bloodline, and Morrigan's "god child" are too ripe to pass up by the writers, I think. Of course, it'd also be cool to have a game where you take on a squire of sorts. Maybe even two. One from Morrigan, and one from Alistair, depending on story decisions in DA:O. Sort of like an invincible (during play controlled combat, not story elements) sidekick/pack mule/servant boy or girl

"Ser, can I polish your armor, ser?" "Ser, I've found some more elfroot like you've asked!" "Ser, can we rest now? I'm tired from carrying Shale."