I've gotten used to dying to riven because she does insane damage and has great chase. That's just part of the game at this point and I don't expect it to go away, but why is she allowed to run away just as well as initiate?
I'm glad they nerfed her movespeed, and I will have to wait and see how much that changes her, but I think the main problem is it's too hard to punish riven.
My idea would be to just drop the dash on her shield, and add on a couple seconds to the duration. That way she still gets to negate some damage after she jumps on you early game, but she won't be impossible to punish as a melee champ. It will provide that much wanted counterplay opportunity to riven I've always wanted.
Note: I'm not complaining about riven, but I don't think that a bruiser should be able to play like an assassin. It's annoying.