Balance
First of all I'd like to say that too many people are freaking out about this patch. Just give it a while and people will play more serious and games will last longer. That being said I think some of the new things definitely need some fine tuning.
Let's talk about the thing that everyone is compaining about warrior's bloodlust. It seems like a good place to start. This mastery favors like 2 champs highly above all else and seems a lot more nich than all the other keystones. Early on warrior's bloodlust is so much stronger than the other 2, you can't even compare. I think that a good way to nerf this would be reducing the heal or removing it. After all it is the offence tree and I think it's kind of weird that lifesteal is in it in the first place.