Next season (Season 8) is the last. I still really enjoy the show although earlier seasons were funnier IMO. I don't understand why people are so frustrated not meeting the mother before last night...once we knew it wasn't Robin and was going to be a random person, who cares what the mother looks like or her name is.
My theory before last night was that Ted and Robin get married but end up getting divorced (or Robin dies), Ted remarries and has his kids with another woman. But last night's season finale ended that idea.
After 'the time travelers', when he talks about how he would have gone and seen her just to have a few more days with her, i think the mother might have died. Would also explain why the kids were willing to sit through such a long story.