I realize it is probably way too late for them to implement something like this, but I thought I'd still throw it out there. I'd love to see traversable glaciers. You could either walk around a glacier, or you could take your chances crossing the glacier. Just like real life, there would be a chance you'd break through a snow bridge and fall to your death in a crevasse. Or, if you survive, you'd have to find your way out through a maze of ice tunnels. They could even take into consideration the amount of stuff you are carrying when you cross the snow bridges. Some bridges could support more weight than others. Of course, there wouldn't be just one safe path across, there would be multiple.
For all the of people that like mazes, it would give you two kinds: one on the surface with no walls and another with walls, inside the glacier.
I fully expect that they have already created some dungeons inside the termini of some of the glaciers, but I figured this would be another cool use for them.