Some things I would not mind seeing later on, this is just me though to my knowledge lol
1. Flintlock Pistol and Rifle (We already have a blunderbus)
2. Skill books to unlock specific guns just like how we get a baseball bat
3. Legendary Vehicles with varied stats
4. Definitely More Food Varieties
5. More Craftable Lighting Fixtures
6. Glowsticks we can throw to illuminate an area (Maybe Attract Zombies with the light?)
7. Flaregun - Mostly for Multiplayer but it could be fun to shoot at a zombie
8. Power Tools - Such as an automatic wrench for ripping tech stuff apart
9. I hope for working camera monitors.
10. Zombie Animals - Imagine having a zombie rabbit come after you.
11. Feral Mode for Crawler - Jumps up and runs at you while active
12. Maybe more special infected that show at higher game stages (Reviver, Male Doctor)
Just some things i thought about