From new Bikerumor interview:

BIKERUMOR: What about 650B?

JM: I think itís coming, nobodyís going to stop it. 29er is going to become the XC norm and 650B is going to completely wipe 26″ off the map. And Iím not against it. I think the wheel size rides good. It gives some of us that arenít using a 29er for everything a wheel size that really could work for everything.

MW: Iíll definitely try it. Iím definitely interested. Iíd like to see what it feels like. Iíve done a little riding on it, but not enough to get a handle. Seems like itís not a big enough difference to be a negative. Who knows, in a few years maybe there wonít be much 26″.

JC: I think it would be a great improvement to the type of riding we do. But first we need to get the geometry dialed.

BC: Iím open to it. Iíve never tried it, but Iíd like to.