More player customization.
Option to download decals and faces as other players come to servers or as you join, so we don't have to keep seeing base decal (blank) and base face whenever there's something we don't have that someone is using.
Yes that's right, you downloaded some decal and face that only like 2% of the game will see.
And maybe in a later version, new coloring system.
Default control to equip spray can, and another button to open the color sliders. Colors save as RGB data on the brick, rather than a number between 0-63. No need for colorsets, and all those datablocks that the paint takes. We also will have more variety rather than just 64 colors per server, and loading a build in a different server wont butcher the coloring.