Hearthpwn

I've been playing since beta and watching the meta never fully change in a general sense. Standard/Wild just shifts the cards but most of the same archetypes persist. My personal opinion is that it is because of the lack of interaction on the opponent's turn. It keeps the game faster and I understand the reasoning, but it is a problem and aside from secrets and taunt there isn't much. 

An "Infection" mechanic would potentially change things up. It would work like this: A minion or spell would have "Infection" and when it damages a minion the minion would lose -1/-1 at the start of each turn. There would be a number of avenues this could take. Infection could spread to the minions next to it after each tick, or infection could hit the initial minion and the ones next to on the first attack. A minion or spell could have a higher infection rate -2, -3, etc. 

It adds to decision points in regard to positioning and would shake up boards so things aren't as static except for AoE.