There's got to be a big release coming at some point. We know they are redoing the UV tools and I don't think we've yet seen all of the new core since the UV tools / Bodypaint are built into the core. So I'm predicting R22 is the big one with new UV tool set, faster object handling, multi-threaded Xpresso, updated Xpresso with more nodes. Has to be otherwise I think there will be a mass exodus to XYZ 3D application.