I just predicted something to Amanda, and I'd like an official record of my prediction. I've heard the rumours that we'll learn the mother has died in How I Met Your Mother.
I tend to believe those predictions. However, I also predict that we'll learn that in "present day" (2030), Barney has also died, and that Robin and Ted are planning their final years together. The arguments that kept them apart in the past will no longer exist. Ted will already have had children, and Robin will have travelled the world. They'll both be in their 50s, and there won't be any reason for them not to be together.
Anyway, that's my silly prediction.