I'd actually like a bounty board type thing added to the traders (instead of those notes you find everywhere, keep treasure maps in loot though)
on every horde DAY (not night) there would be a special bounty for a specific enemy type during the horde that makes them more likely to drop bags (say its normally 1~5%, bounty ups it by 5% per horde night {capping at 25% on day 35}) with say 50 higher loot table chance (still could get useless junk but will be higher amounts of said junk, but chances at good stuff as well)
Notes (kill x type zombies at location like normal)
Bounties (kill specific zombies at location {have small stories like "The zombies in Shamway turned/ate my dad, please kill him before he kills more people ~Susie~" {either kill the dad for turning, or the attacker for killing the dad}
the bounty target would drop a loot bag with an identifying item ("Dad's wedding band/Bloodied baseball cap") that we turn in to the trader for the bounty (straight Dukes and XP, no items but higher amounts of both since the areas might be more populated with enemies.)
Just an idea that might appeal to late-gamers, since early game most people want items to advance quicker