I just got out of my first game as Ryze since the patch. I feel a little bit like crying. The damage on his ult was lowered by 60 damage per bounce (at level 1). That's a total of 180 damage if used in a 1 on 1 situation. That 180 damage IS the difference between life and death in most situations. His early game ganking ability is gone, and without it, he does not have much left. He was never all that useful in team fights. He dies incredibly fast. He can not creep for ****. He can't jungle. He used to be pretty awesome at taking down turrets, but now that they have magic resist, he isn't very good at that either. Rune prison and overload are both pretty solid skills but are on such long cool downs that you rarely get to use them more than once in an encounter.
This nerf was totally out of the blue and really quite unnecessary. People have been crying about Ryze's ult since the game came out but I think most of the higher level players agreed that Ryze wasn't a huge threat overall. Before the L2P people jump all over this one, let me just say, we are talking about Ryze. Their isn't much L2P going on there.
The bottom line is that this nerf has taken away his only strength, his ability to be an effective low level assassin. Without it, he has nothing left and feels incredibly weak in game.