Tamron have launched a new 70-300 zoom lens. It's got vibration compensation (VC) and uses their new ultra-sonic silent drive (USD), as well as as an extra-low dispersion (XLD) element. Full name is SP 70-300mm F/4-5.6 Di VC USD (Model A005)
Initally launched with a Nikon mount, Canon and Sony to follow.
More details here.