It looks like the new Traxxas Spartan ESC is programmable through Castle Link. If you look at the images folder inside the program files of the latest castle link you will see a Traxxas Spartan image that seems to suggest the it is programmable! Don't take my word for it, try it your self f you have a Spartan.
Here is the image gallery: https://picasaweb.google.com/ctech.ab/CastleLink?authuser=0&feat=directlink
