over at publish.it168.com got a hold of an RV730/HD4670 card and put it through its paces.
Apparently ATI's new mid range card packs quite a punch, and it can even keep up with the HD3850, trailing behind by only a few FPS in most tests. In Crysis it is twice as fast as Nvidia's 9500GT.
The RV730 has the same number of shaders as the venerable RV670, but it uses a 128-bit memory bus. The HD4670 will be clocked at 750MHz, while the HD4650 will end up at 600MHz.
Both cards should launch in late September.