I do a lot of procedural generation, and you can do some things really well.
You can generate whole planets worth of terrain that looks lovely, you can generate plants, characters, weapons, almost everything.
You can't procedurally generate game play.
It's an area I am actively working on, but so far it's a real issue. I have written some very scary genetic code to experiment with.
The other thing that is a real problem is very clearly shown in Borderlands 2. They make a big thing of the weapon system, what do they advertise, 4 billion weapons?
What they have created is a system that makes opening a treasure chest boring. "Oh look I have found ANOTHER rifle, this one reloads 0.02 seconds faster than mine but does 1.03 points less damage." (please read that bit as if you are a health and safety officer lecturing about the dangers of pencils)
At the moment you need a human to decide when procedural generation is a good thing and when we need a human.