Tools, Arms and Armor
As the title suggests, I'm hoping for an expansion beyond the standard Assault rifle and space suit. Granted its not as essential as the Welder, Grinder, and Driller tools, but it would be cool to see something like Sidearms, Sniper Rifles, shotguns, heck even a rocket launcher. It would even be neater to see some melee weaponry to be found in there, if only to have these no longer be mods and make the gaming experience smoother.
As for Armor, no brainer, I would love to see more suit variations like what we see on the workshop. Combined with the awesome skins you've been dishing out for some time now, I'd think they and the new weapon/equipment would be amazing
...that and having all that vanilla would cut down on the mods used in game.