I dont want high mobility as a lock.. I like the idea of being a tough, resilient caster who uses magic to shield myself, minimizing damage.
I want survivability. Make us tougher, stronger, more armor.. something, especially since I'm demo. Moving around all the time means I'm not doing any damage.
Many good ideas here!
My personal opinion. Since hand of guldan is one of the coolest visuals and most gratifying sounds in the game. Make it slow or make the amount of shards used increase its damage per shard spent