I've occasionally thought about resurrecting Villains Victorious! or otherwise publishing it in a collected format. My reservations there are practical - to put out a high-quality PDF of the material, I'd want appropriately four-color art.
Similarly, I've got a decently polished sci-fi concept (Song of Eden) and the start of some unconventional urban fantasy (Fairy Soul). I have enough ideas that I could assemble a fantasy universe, but that would take more time.