Of course, Stalhrim is used by the Nords to bury their dead, (so how did the Draugrs come about?) and in Bloodmoon, it could be mined to forge/get powerful equipment, with the help of NPCs of course.
I'm wondering if Stalhrim will be a useful resource in Skyrim. It should most probably make a return, since it's very Nordic, but hopefully we will still be able to use it to create equipment, either by ourselves or via NPCs. Or perhaps it be considered a crime to even possess Stalhrim as it could be interpreted as the disturbing of Nordic tombs?
Also, if there is no medium armour in Skyrim, would Stalhrim armour, if any, be Heavy or Light? Personally I hope if such a thing happens we can craft two different variants, heavy and light, of Stalhrim armour.
On a side note, where does Stalhrim come from, before it's used to bury the Nordic dead?