Tamron has announced that its SP 150-600mm F/5-6.3 Di VC USD telephoto zoom will go on sale on December 19th in Japan, and 17th January 2014 in the USA. The lens will feature optical image stabilization and an Ultrasonic Silent Drive autofocus motor, and be compatible with both full frame and APS-C SLRs. It will be available first in Canon mount, with Nikon and Sony versions to follow. Pricing is still to be confirmed.
News: Digital Photography Review (dpreview.com)