SMT has been on desktop for over a decade now, and Windows scheduler still have trouble making sense of it. Oh, and people now know that SMT is a security nightmare, due to inherent nature of resource-sharing design. If you want to share your bathroom with your guests, you'd better be sure you have no skeletons in the medicine chest.
I'd say SMT's time has passed now that core counts are actually increasing. Back in the day when the CPUs had one or two cores SMT made sort of sense, but today AMD and Intel's time will be better spent figuring out how many actual cores they can fit in a limited space without sacrificing performance/power.
AMD already tried to make a convoluted resource-sharing scheme work and failed miserably. It's called Bulldozer.