It needs a lot of work and only generates a height map so far and you get a endless flat plane if you go into negative numbers(can be easily fixed by not starting near (0,0,0))
probably will be useful in some games
https://docs.google.com/open?id=0B4Kgy_Y2LJJ2WUhUY1VvOWVSVzQ
just do file->Download
Just to be clear this is not an editor thing but works at run time to generate terrain around the player making for thousands of kilometers (I think this version has it in 10s of thousands of kilometers, then it starts to repeat) of playable area but it is only really limited by how far from (0,0,0) Unity allows objects to be. Currently you can travel at over 5 kilometers per second and it will have no problem keeping up( on most commuters) and running at 60 fps