In my honest opinion I think ted and robin will end up being together. How I came to this conclusion is i believe the older TED is telling a story of how he met there mother. Which doesnt necessarily mean that the kids are his but instead he could be the uncle. And Aunt Robin could be Ted's wife later in life. I can't recall if older ted ever reference himself as the father. Also i couldnt see any mid-new character, like Stella being the one for Ted. It just seems Robin is the one with the first date "I love you." It could also be a big surprise to find out those kids are Barney's kid. But there are reference to "Uncle Barney" from older Ted.
I feel i could be wrong, but it's a possibility.