Most of all, i would love to see physics in hair.
We have boobs physics.
Unity 5> can make hair physics.
Maybe computer requirements would have to raise too much to support it, but devs should make it as an options in the graphics settings.
I think hair physics would add a lot of realism.
I am not a programmer or a 3d creator though.
boob physics doesn't interact with other objects, Hairs would have to have collision and yes, unity is capable of but the performance inpact is huge, just check tomb raider and how much it costs...