Jorge
I don't agree. This was the very end of Ted & Robin's relationship as the episode's names is Something Old, being this relationship that something old, and the next episode being named Something New being somebody else (the mother!) that something new.
Winona
Wrong. He always calls her "Aunt Robin", and so do the kids, so they can't be adopted, 'cause they wouldn't call her aunt.
And well, there are a lot of other things that prove that they don't end up together... like that scene, where Robin is dancing with her dad at the wedding (which means that there was a wedding) and Ted sees "the mother" across the room, playing the bass guitar. Or that other episode where he says he loves when "the mother" sings in the kitchen or that he loves her paintings, describing her as Cindy's roommate.
So yeah, I think that scene in this last episode was just something to make us doubt about everything.
