The robot workshop is already pretty far along, and people have started making and sharing their .RR2Bot files. Check out these awesome Nightmare and Bite Force replicas by GameTechMods user Arcane:
By the time the game is ready for full release, it should be possible to replicate any robot at any weight class. Once a robot is replicated, it is pretty easy to share it around as an .RR2Bot file. Right now we have partial support for Beetleweight and Heavyweights, and should be adding more and more components as time goes on.
We started down the path of an arena creation tool, but we had to stop work on it because of time. We don't have permission to use BattleBots or Robot Wars IP in the game, though who knows what the future might bring?