I'd also like to see the option of marriage in future games, with the limitations addressed previously in this thread (ie. only being available to certain LI's with the appropriate backstories, or some LI's requiring you marry them). With marriage being such an ingrained institution worldwide, I was actually kind of surprised/confused to see it never really show up in either of the previous Dragon Age titles, especially after the developers worked so hard to create fully fleshed characters for us to fall in love with. Granted, a ring on one's finger doesn't change the feelings one has toward another, but at the same time, said ring is more than just a band of metal (or wood or what-have-you), and I think it would be a rewarding experience to be able to see and hear the effects of pursuing a relationship that far.
My concern would be more along the lines: Would it's optional nature frustrate people? Because by virtue of it being optional, it runs the risk of not being satisfying.
Would people be okay with it if it was "yes lets get married" but there was no real wedding scene, for example?
What things would people expect that they are just sort of taking for granted now, but when playing the content they would suddenly notice and it'd be seen as subpar as a result?
You bring up valid concerns, of course, but I believe that as long as the marriage option was implemented with as much care as the current romances, people would be more than satisfied.
Just a few things I can think of to be added that would (in my books) be considered a fully realized marriage:
- additional in-game banter regarding the marriage (much like what is already in Origins and DA:II with respect to developing romances)
- perhaps additional dialogue with one's spouse regarding their future (something that, when speaking with them, reinforces the idea that the two are married)
- sharing a room/bed, if applicable
- small marriage scene (just the two, or maybe allow the player to invite the companions), although I can see other ways of handling the event
- (maybe) an additional epilogue slide/VO/whatever-is-being-used
At the same time, @Icy Magebane makes a good point: whatever is implemented would have to still allow the majority of romances to continue without a marriage for those players who simply prefer to play without taking that path.