The new Pentax HD-DA 16-50mm f/2.8ED PLM AW lens is now in stock for the first time in the US at:
Additional information on the new lens can be found here:
HD PENTAX-DA★ 16-50mm f/2.8 ED PLM AW lens additional coverage
HD PENTAX-DA★ 16-50mm f/2.8 ED PLM AW lens officially announced