Tamron is rumored to announce a new SP 150-600mm f/5-6.3 Di VC USD G2 lens for Photokina. The model name of the lens will be A022 and will be available for Canon, Nikon and Sony mounts (no VC in Sony version). The "G2" probably stands for "generation 2" (Tamron already has a SP 150-600mm f/5-6.3 Di VC USD lens). The official announcement is expected for Photokina.
Update - here is a picture of the new lens:
In addition to this tele zoom, Tamron is also rumored to announce a new wide angle zoom lens.
Via Nokishita