Tamron has continued to add lens motors to some of their more popular lenses (which makes them fully compatible with the Nikon D40/D40x/D60 line). The latest recipients are the 28-300mm f/3.5-6.3 lens (which has image stabilization) and the 28-75mm f/2.8 XR Di LD Macro. Also, the 70-200mm f/2.8 Di LD Macro will be getting a lens motor in an upcoming update. These lenses are expected to be available in June in Japan; availability elsewhere is unknown (Tamron USA hasn't even announced the 70-200mm change as I write this).
I've gotten a couple of reports from site visitors about focusing performance on motored Tamrons, I'd be interested to hear from more users about their experiences.