While not much is known at this point, we know the disc is on the way to the testers sometime in may if all goes well.
Most predictions as the the stability of the disc have it more along the lines of a Boss at best though most people are hoping that it will be the more Ape like disc. Ultimately Vibram, in my best guess will have two more distance drivers that are more overstable than the Lace.
A Boss isn't overstable though....