Well, it's certainly a huge step in balance.
First of all, I like the removal of some of the chance effects (ie. spells were changed to have 100% chance). Still, don't forget there are multiple layers of resists
Nerfs were made to all classes. I guess most of all hunters, locks and barbs. Considering rvr, perhaps a good change, in pvp this will be a pain. Some of my setups will have to be reworked from the scratch.
Nerfed knocks, darkness and some other cc's is a good change. I'm still concerned about barb damage, knight defense, and especially mindsquasher. I hope some changes will come in future.
To be honest, the changes are too widespread to be balanced out in theory, we will need a few weeks to see how they work on live servers in order to see how things turn out.
I'm glad to see something big coming, it should be fun