Just saw on cgtalk that they’ve released this tool for free.
Some of you have seen the Roboblitz game with the ingame procedural textures, well this is based on the same technology, only it outputs to maps instead of directly to the gameengine (would be awesome if they’d port it to unity instead of keeping it for unreal3).
Still, seems you can do very nice things with this.
And can be found here: http://www.mapzoneeditor.com/