So, it's a wild topic on many different forums, so I thought that I should give my two cents about how I think the show will (should conclude)
The clues. The hints. The build up. The name dropping by Jerome. Destiny. I think that there is simply too much going on, for Carly Whittaker not to be The Mother. We all know how Thomas & Bays like to plant false thoughts into a viewers head, but this one seems like it will come true. Ted will meet her in the very final episode of the series, as revealing the identity before then would only kill off the central reason why people watch the show. Being Barney's sister is her reason for being at his wedding. It has to be excecuted correctly, and I think Carly will approach Ted after he gives his best man speech, as she will be taken back by how deep Ted really is (we all know his toast will be epic) and she will have much curiosity about him, seeing as she's had many close encounters with him prior (the apartment & the classroom) It has to end this way.
As for Barney... well I never thought that he would marry before Ted, but here we are. While this doesn't directly relate to how the show ends, I think his love story will end with either Nora or Robin. Quinn will be the woman that finally changes Barney's attitude toward life, as he will be left with a cold hard dose of reality after dating her. I think Quinn will act like a Hurricane. She'll come roaring in, raise hell, change the landscpae and then leave. That is her purpose in Barney's life, nothing more. I fear that Robin will be the bride, simply because so many fans want it to happen that way, but that's the easy way out (though with Lily dressed like a Bridesmaid, this might actually happen, sadly). As stated above, I hope to god Nora is the bride. She is the nicest girl, yet she has that intruiging aspect about her. The major drawback however, is Nora and her self-respect. It's a lot to ask of her to marry the man that cheated on her. But who knows? Bareny's new personality after Hurricane Quinn might prompt him to fight for her, and make it right. And let's not forget Nora's own words at the conclusion of Season 6. "It's never too late Barney"
Ah, everyone's favourite Canadian. Don't get me wrong from the above post, I love Robin, I just don't like her being involved with Barney. She's gorgeous, funny, and she has attitude, What a woman. But for all her independence, one man got to her more than I think the show let on. That man was Don Frank. Don is the only love interest of Robin's, to ever show more independence than her, with him walking away from the relationship to pursue a better career. The tables have been turned on her big time. Robin was SHATTERED at his choice. She showed how much she wanted him by putting love ahead of her career. That my friends, is not Robin. But that's what love does to us, it removes us from our comfort zone, and makes us chase, and chase. I know it's left field, but I really want Robin and Don to end up together. For all his juvenille antics, he grew on me. I liked him by the time he left. Him leaving, only made Robin's feelings stronger deep down. The only reason why she didn't call him, is because she forgot his number. That's not the closure that this deserves. I think season 8 might have a few surprises in store, and I hope this is one of them. They truly worked well together as a couple.
Marshall and Lilly
There isn't much that needs to be said about these two. They have what Ted has always wanted; true love. I think that they will have 2 kids, a boy and a girl. Marshall will become a very sucessful environmental lawyer, and Lilly will eventually quit Kindergarten teaching and soley focus on her paintings. I think there is a lot to be learned in love from these two, and I'm glad the show has given them enough air time to have thier story told. As I said, not much needs to be said, but when you have the perfect love story, there isn't much to report on here. Till death do them part.