that's like saying not to add a carpet because we have the flying jeep
Carpet is there for nonwheeled flying vehicles, flying jeep is there for wheeled flying vehicles, because the two work a bit differently.
Personally, I just think a default-style shotgun, rifle, and machine gun, to show people how to make those sorts of weapons. And maybe some new bricks, because it's darn hard to make some things without certain packs.
Onerandombrickpack, Wedgebricks, Wedge print, etc. etc.
GSF's bricks need a little fixing up before they can be default, but someone was working on it last I heard.
Actually, we also need:
DiagonalRiver/Rapids (has been made)
Up current water, down current water, up-side, down-side, up-diagonal, and down-diagonal.
We could use the ColorWater and ColorFire emitters too.
Of course, if you expect any of this to actually happen, you need a reality check. It's like whats-his-face said a page or two back: It's not gonna happen.