>>972471Roslagsbanan is undergoing an extensive double-tracking.
The most likely extension is a small rebuild in the north to the town of Rimbo, a part that should never have been torn up. For the past 30 years the only thing that's been missing is money.
A branch from Vallentuna to Arlanda airport has some sketchy plans to it.
In the south there's just whatever railfans come up with. Some calculations of the benefits have been done, but not to extend Roslagsbanan south but the Red metro line north.
God knows about the yellow line. From what I've seen they're straing themselves blind on saving a few pennies by using bits of tunnel on the Green line that were built for a possible branch that later became the Blue line. The perceived savings can be good though, Tvärbanan was built on the idea that streetcars would reuse already installed industrial tracks (in the end the only work/money saved was that of zoning).
