Personally I'm quite certain that as people slowly beggin to use the tool, more and more people will as well. It will be a slow rise, but it's no problem.

It would help, too, to prepare for modding Doom4 in the future. It'd be like practice to use Rage's mod tools, even though Doom4's will be changed perhaps in many ways.

You won't be able to mod the game much anyway making it only attractive to hard core id modding fans and people just wanting to dabble.

Steam Workshop could help to ressurect interests into Rage and as a conclusion bring modders to the tool kit

A certain amount of modding should be both practical and possible. Gameplay changes should be reasonably straightforward to implement: one that immediately springs to mind is a "no, you don't actually have to do the races" mode.

a few mods would help bring new life to the game.....we will see i guess

That's the kind of mods I expect. I'd especially like to see weapons mods that increase the difficulty level. Pop rocks that hurt you when they explode too close and things like that.