Rachel Bilson has scored a spot on the 100th episode of HIMYM. It hasn't been confirmed that she will be the future Mrs. Mosby, but she definitely fits his archetype: Thin, attractive and a brunette (we know this much). Carter Bays says that Ted will be "so tantalizingly close, its ridiculous" to his future wife.
What do you think, will Ted meet his happily ever after in this episode? I doubt it, once he's met his mother, that's the end of the premise. It will be nice to get the yellow umbrella question answere though.