Tamron have one new 18-400mm f/3.5-6.3 Di II VC HLD superzoom lens to announce for APS-C DSLR camera. This new Tamron lens will be announced along with SP 24-70mm f/2.8 DI VC USD G2 lens
Nokishita Japan have leaked this info means the lens would probably be announced this week.
But before its announcement the images of those lenses have been leaked online. See below: