Have I been waiting....no. I've been using the 24-70 II and it is remarkable. Plus, for what I use the lens for, my best shots either come from a tripod (landscapes) or with fast enough shutter speeds (people) IS is not needed, so, for my shooting, I really do not see IS as all that necessary. It would sometimes be useful, sure/maybe. For me, I am getting a long just fine without it. As another example, I really do not use the IS on my 16-35 f/4 IS. But, IS on telephoto lenses is absolutely used and much appreciated.
No, I do not expect an EF version of the lens.
Yes, I do expect it to only be an RF lens.