My hope realistically.
Barrels weight get changed so you can only carry around maybe 1 with a very strong character.
Jump/disengage now becomes an action not a bonus action.
Enemies losing some of their "endless" bombs and special arrows.
Raise cap to lvl 5. (doubt this one will happen)
Better AI when "they can't find a path to you" Perhaps they run out of LoS of you or something.
Little more stability.
Adjusting some of the monsters HP and AC values to be closer to 5e MM
What would blow me away!!!
Another class to try out. Any of them. But I would hope for Pali or Druid.
1 or 2 more magical artifacts that don't you know... suck.
Little more exploration.
A few more options in the character creation.