More ore types thus allowing us to craft more items, armour types and weapons etc...
More biome types
More crop types
An end update such as more mobs, perhaps some kind of ores, more structures and blocks
More animals and creatures such as different bird types, perhaps small insects
More variants of animals for example more breeds of dog, different colours of cows and chickens like we have in the real world
More food options, nothing too modern but more options would be nice
More decorative items
More mob heads
And the part that let you edit what different layers your world were made out of before you made them before it was pretty fun, as well as more world customization options eg number of villages, size of villages, proximity of villages
A long list but it would be nice to see these things in the distant future