I was wondering if I'd ever bump this thread again.
I just saw the season 6 finale. Looked like they were hinting at Robin being Barney's bride. That was quite a cliffhanger.
The only thing that's throwing me off right now is the flash forward to when Barney was pretending to be on his death bed to get back at Marshall. It's hard to tell if he was married to Robin or anyone else at that point. Then again, that incident could have been a gag that Future Ted threw into the story.