I definitely want to see my Wardens back, badly. I didn't replay the game five times just to watch my Wardens disappear. I want them voiced, I want them to reflect whatever major status choices I made with them, and I want them in the game.
How?
Integrate them into the main plot wherever they each make the most sense, or for whatever plot they have in mind if it's after the Warden's disappearance. Yes, a cameo appearance, but a major one at least on par with the major cameos in DA2. At least that.
Get all the possible Wardens in this particular game because of the oversight of not including them in DA2 even though most LIs were present. In the future, if a particular Warden doesn't have any reason to show up (like if there's no Fereldan royalty, a monarch Warden might not make sense, just as an example), then that version just doesn't show up. Just integrate them, don't shoehorn them where they shouldn't be.
Give us the ability to import and edit their appearance or just edit them from preset options (preferably as a pre-game option right along with character creation).
Give us the ability to clarify the Warden's stance on the issues, seperate from our import decisions. (Friendly to elves? Pro-mage, pro-templar? Opinion on dwarves? the big easy true/false questions, and then Religious stance, probably, though they should be able to get that from imports) That way there is no contradiction on what you would have your Warden do were you controlling them and what they'll have done off-screen in the game.
Give them six different VAs to reflect wherever they come from (or less if you have an actor that can do multiple credible accents), and treat them like a set of six major NPCs, just like former companions.
*IF* there's enough budget room or the cost is practically the same, then go ahead and let us choose a personality template exactly like Hawke's set of personalities. Otherwise, go with what's closest to the in game Warden. The Warden, no matter how you played them, was pretty terse. Every response was a one line thing, no matter what choice you chose, so build the personality up from that. (not saying they should be restricted to one liners, but there are no prolifically wisecracking or soliloquy spouting Wardens, even if your warden liked to joke here and there) So, matter of fact for the most part.
Just come up with a few different suits to reflect the class of the Warden and a few weapon sets if we ever see them fighting. No need to import armor and weapons and all that. class specializations would be cool, WOW! moments to see in action, but not necessary.
For Hawke, just let us import and edit or choose a preset and edit just like the Warden, import the dominant personality, and give us the stance checklist. Have him/her show up wherever they disappeared off to, on one side or the other, with the chose LI, and that's it. Not hard, really.
For me, the Warden's a heck of a lot more important to see than Hawke, but I do want to see them both. There's zero reason they can't do both to exceed our expectations, never mind meet them. People just make things seem harder than they are, and they do it all the time. Just do it. Please don't worry about the boards. If people can't see it, just prove them wrong.