hm, at first I was going to say man they took out darkness. But then I thought about it and I think that this idea is pretty neat imho. Also, it fixes perhaps those builds where someone could see through the darkness somehow and then would carry a continual darkness stone and just hammer on people. This would be an eerie shadowy world.
*shrugs* I like it, but I guess I'm starting to be a 3.5 fanboy as even the most harsh changes I'm coming around to.
Tellerve
EDIT: although it does raise the question that you could just throw down this darkness and then run away as they'd see you, albeit shadowy you. Although it would allow you to hide...i think, although you could be considered to be in view. hmmm