Tamron is rumored to announce a new 17-28mm Di III VXD G2 lens
CameraBeta reports:
Tamron 17-28mm F2.8 Di III VXD G2 will be released later this year. This new lens uses VXD drive to achieve faster AF speed and accuracy. The lens is expected to go on sale at the end of the year. (Previously there were rumors that it was June)
Tamron just recently updated the 28-75mm lens to version II. So I definitely expect the wide angle zoom to be updated too.