My guess is that - if some of the rumors are true and Stark goes off into space to help set up the Guardians of the Galaxy movie - or Thor 2 - which is really more my guess as to the purpose of the Space Armor - since it seems like each Marvel movie since Iron Man 2 has helped to set up the next movie in the line. Like IM2 set up Thor. Thor set up Captain America. Captain America set up Avengers. Avengers set up Iron Man 3. And since Thor 2 is coming out this fall - my money's on Iron Man trying to find a way to get to Asgard. Which could always mean he also bumps into the Guardians of the Galaxy.
So I'm thinking maybe the "Tragic" thing would be him and Pepper not really "Breaking up" but leaving her for a while to get his head straight.
I'm not entirely sure we'll get a Rescue armored Pepper though - closest I think she'll get to a suit is one of his. But maybe we'll see a set up like they did in the "Most Wanted" arc where she gets mad and throws a vase at the wall and the wall opens up and there's a shiny new Rescue armor waiting for her and just leave it vague if she actually puts it on and uses it.
The Iron Legion "spoiler" some one mentioned I suppose could work - after all Stark only really used the "Legion" controlled by his Extremis a couple of times in the comics before they both trashed a bunch of his suits so he didn't have that many to call on anymore and then after the Skrull invasion, the Extremis was pretty much wiped out. Bleeding Edge was a new system. As I recall his explaination was.
"Extremis was the OS. But without Extremis, I'm still Extremis class hardware."
So while he had this super armor that hid in the hollows of his bones and instead of just the undersheath he had with the original Extremis, he had the entire suit inside of him and could reconfigure it all kinds of ways. Something, while very cool at the time, coming out of the old Extremis comics - I'm glad they eventually did away with and had him back to regular old suits. Almost seemed to make him too powerful in a way. Sure they could put an inhibitor thingy on his Arc reactor but even so.
Although my big question is - with all the suits he built between Avengers and Iron Man 3 - do you think he used other workers to help? I mean, he's got a weapons manufacturing plant at his disposal and since the first Iron Man movie - I'm sure that production is not where it was before he became Iron Man - so I'm sure there are plenty of workers who are skilled enough and background checked enough and loyal enough to help Stark build parts and elements for his suits.
A few suits built in his home fabricator - okay. I can buy that. If I had a robot controlled CnC machine and a JARVIS system, sure okay. But I seriously doubt that he could have built every single one of those suits by himself in his lab and still have time to keep Pepper happy and gallavant around as a super hero every so often.
I'd actually think it'd be a cool break from the comics where new armor just magically seemed to appear from nothing in the span of an issue and actually have real people working on the suits or at least building parts of them. Heck just making under armor armature alone has to be a bit time consuming. Even for a genius, it was still hinted that it took him almost a month or so to build the Mark 2 and 3 in the garage. So even if they say Iron Man 3 was a year - which I know they aren't - after Avengers - that's still maybe 10-12 armors - which is implied that there's far more than a dozen. And that's saying that Tony and Pepper spend only a few hours a day together and he eats every meal in his garage, never showers and never goes out.