Consumable ammunition has been removed from the game. Arrows and bullets no longer stack, but are not consumed. Ranged attack speed bonus gained from quivers and ammo bags will be preserved in a different capacity.
The consequences of this, frankly, make my mind boggle this early in the morning. The extra bag slot. Engineering shot rendered obsolete. No more 'oh sh*t I only have 600 arrow/bullets left, I'll just HS, brb' moments. One of my best-selling AH items effectively extinct, overnight.
I haven't bothered looking at any of the other changes yet. I'm still staring at this one, slack-jawed, wondering how I'm going to cope after four years of bullets and arrows with just one item in my ammo slot...