I'm thinking there will be some off the wall gimmick just like that to stretch the story one more year. I still don't think we'll meet the Mother on this season's finale. Maybe Ted will go back and say, "I forgot to tell you this story!" and "This is a really important part that happened several years back, but I saved it until the end."
I really liked this week's episode. One of the coolest parts was when Barney yelled "It's Robin Sparkles IV ya'll!!!!!"