After the Ending (spoiler)

As for getting back home. What home? The only thing beyond the city that anyone has any memory of is Shell Beach and that doesn't exist until John creates it.

There is hope but only that they now get to make the best of what they have... which is pretty much the same as what the rest of us get to do.

Only the closed mind is certain.

His name was John. Maybe you haven't seen it in a while?

The film's conclusion is quietly optimistic in an outward way, but actually, a moment's thought reveals John's situation as extraordinarily bleak. He is the sole member of his society who knows he once had a family, friends, a life of his own...which he can never have returned to him. He can tell no one about it, have no one empathise with him, and he must carry this burden, along with the knowledge he is floating through space on a virtual Ant Farm, for the remainder of his artificial, manufactured life.

Horrific...unless you consider he gets to bang Jennifer Connelly in one of the last movies she was ever ridiculously gorgeous in.

Your observations are correct, which is why I like to use Dark City as a great example of the difference between a movie that gives the audience closure and a movie that actually resolves everything at the end. DC gives closure -- the story reaches a natural stopping point and the conflict that drove the main plot of the film is finished. DC, however, does not actually resolve everything at the end, as you point out.

In terms of what the future holds for the characters, somewhere in the bonus materials on the Blu-ray, I believe that Proyas says that he had an outline for a sequel set years in the future where John has become a "mad god" ruling over the city and Emma/Anna along with their child (who would also have tuning abilities) has to redeem him. I doubt we'll ever see such a sequel though.