I'd like to see an episode where they flashback and insert her into some of the scenes where they insinuate that she was there (Ted's class, the club, the roommate, etc). Ted still can't have contact with her, but still, going back and redoing those scenes with her would be kind of cool.
It's almost a guarantee that we'll see those, plus maybe other close calls. It would be terrible fan service to not do those things!
I'm still holding out hope that they are able to get someone like Lori Loughlin to do some voiceovers about how she met Ted, even if it's only for one episode. Scrubs did a couple of those episodes every season where someone else narrated for a while (Those episodes were usually called "His..." or "Her..." instead of "My..." like all the other episodes) and the show is told through someone else's perspective.