Breaking away from the "Is the Mother Dead?" storyline, there are some other questions that might be brought up by examining when the last time we've seen the major characters.
- Ted - 2030 (vocally) - telling Penny and Luke the story ("Pilot" - "Rally" [no appearance in "Vesuvius"])
- Ted - 2024 (physically) - A snowy night at the Farhampton Inn ("Vesuvius")
- Marshall and Lily - 2029 - Marshall opens Lily's death letter ("We're Not From Here")
- Barney and Robin - 2021 - The exploding meatball sub redux ("The Exploding Meatball Sub")
- The Mother - 2024 - A snowy night at the Farhampton Inn ("Vesuvius")
Ted makes it to 2030. No questions there at all. He's telling the story and regardless as to his mental state, physically he's there. One can assume that Marshall and Lily do as well unless something major occurs in that year. The Mother, well, that's completely up in the air and while everything seems to suggest she might not make it to 2030, it's a big question mark. Then there's Robin and Barney. While there are somewhat contemporary mentions of Robin (the pictures the kids draw of her and apparently references to a trip to the zoo). Putting those into account Robin likely is still around in 2030 but Barney?
Well, where the hell is Barney? He's not referenced in the present tense in 2030 at all. Dead? Prison? Back to womanizing?
I'm not certain I'd be okay with the idea of killing off one of the major (not to mention most popular) characters of a comedy even if it is a plot point to get Ted and Robin together in the last episode. Sigh. I get a feeling I'm not going to like the final episode.