David, I suspect you're right that the Supreme Court will eventually take one of these cases and overturn their prior precedent, Watts : I think that's one of the results that the Booker / Blakely revolutionaries hoped to change. What are the odds? I'd say about 75 percent.
As for whether acquitted conduct should not be used to enhance sentences, I think the issue is the standard of proof used for enhancements more than the fact that the conduct was acquitted conduct by a jury. If the jury decision is given some sort of res judicata effect but the sentencing standard is still below proof beyond a reasonable doubt, then a smart prosecutor might opt not to bother the jury with the extra stuff. He might get the defendant on the basic charge and then just wait until sentencing to throw in the rest under a lower burden of proof.