Tamron just announced a new 18-270 model with "PZD" AF. Seems odd that it isn't USD like their new 70-300. ANyway, it's avaialble in like a week:
"The acclaimed Tamron 18-270mm VC ultra zoom for APS-C format DSLRs has reached an astonishing new level of compactness, performance, and speed with the addition of PZD (Piezo Drive), an innovative ultrasonic autofocus motor based on an advanced piezoelectric design. The result is a lens that's considerably lighter, and noticeably shorter and slimmer (filter diameter: 62mm) than any previous lens in its class, and provides faster, quieter auto-focusing. Signature features that have made this amazingly versatile lens the world standard in its class have been retained. They include a 28-419mm equivalent (15X) zoom range, an improved, lightweight, compact Vibration Compensation (VC) system, macro focusing to 0.49m (19.3 inches) throughout, and, of course, superlative imaging performance."
One cool thing is that it seems to be roughly the size of the old Tamron 18-200, which was really compact.