Deciding that all that talent was going to waste on mere "art", Valve are going to put Team Fortress 2's fanbase to work, giving them the chance to craft their own in-game items, weapons and avatars.
It's part of the new "Contribute" site, which will allow TF2 fans to submit their own ideas for things like hats and guns to Valve. Those deemed worthy of inclusion in the game will be, yes, included in the game. For everybody, too, not just the person responsible.
You can submit stuff right now, with a gallery due "soon". And soon can't come soon enough, if any of the recent fan-made class update pages are anything to go by.