Usually when Companions do this, and they always do, they're changed by the adventures themselves, but in Amy's case, her adventure started with Amelia, so that's where it has to end: Not on her wedding day, but in her own repair. Bringing Rory along to Venice could then be the Doctor's way of forcing her to include Rory in her calculations -- to bring him into the trap with her, to help the Doctor save her -- instead of thinking she could leave him on the slow path forever. And all things being equal -- that is, leaving out the totally gross gender iniquities that are all over the place, just like in most stories -- that's pretty awesome.
It gets to the relationship between Companion and Time in a wholly new way, while somehow indicting Rose for her treatment of Mickey by responding to it. Which is obnoxious, I think, except that was Rose's story, not Mickey's. And this is anybody but Amy's story. And I wonder how incomprehensible all the soap opera stuff was, over the years, for people who don't live in that world -- maybe those are the people who would want Mickey avenged. So while of course I assume I'm right about the ways men and women should treat each other, it's not really interesting to me to persuade anybody else of those, to me, facts.
If I think of how very little I ever cared about poor old Mickey, I can totally acknowledge that if he'd been a harpy in a short skirt -- or Jackie Prentiss-Tyler, for example -- maybe I'd have felt differently. I would have cared very much about his lack of personhood, and felt he was terribly mistreated. I would still be cutting myself off from reading the story on its merits, because either way it's up to us to cross the bridge to the world the story's actually situated. This is a story about men, written for men, by men. We just live in it.
"Okay. This is the real one, definitely this one. It's all solid." Amy is reminded that the TARDIS felt solid, too: "You can't spot a dream while you're having it." The Doctor waves his arms around madly, as this one is prone always to do, wonderfully, searching for pixilation and motion blur, anything that means this world isn't real. We learn that Rory has become a doctor! "Not a nurse," the Doctor points out. "Just like you've always dreamed. How interesting... Your dream wife, your dream job, probably your dream baby. Maybe this is your dream?" And Amy's too, Rory hastens to point out. After a moment she agrees, but the point is made: She has two dreams, too. And now that Rory's seen the stars she's not alone.