PVP enrages me to no end. Its not the losing part of it that does it, it's the pure disinterest in working together. Even with EXPLICIT instructions in chat, people will still do whatever the hell they want and bitch and moan when something doesnt work. I guess everyone does indeed believe they are Rambo.
Wait, does this mean that Warlords of Draenor will probably come out around the same time that X-Men: Days of Future Past will come out? Cue all the dumb people who don't understand how time works claiming how Metzen ripped off the movie (and not the animated series or comic), or how the movie ripped off WoW. :D
I'm going to guess Hearthstone will have some major annoyances. Currently, they allow 'while in play buffs' to increase health, even after the minion leaves play. Apparently it's intended, but not stated, and can result in bad play.