The 6100/6150 _are_ Nvidia's current integrated parts, though they've been out at least a year. The clock rate for the 6150 is ~10% faster than the 6100. The 6150 does much better at scaling video for full screen playback, that's the real difference, not 3D performance.
The G965 is the only Intel integrated solution that supports Shader Model 3.0 in DirectX, and that's the critical feature. Anything with a Q965 or GMA-xxx (G945, etc) will not have the same appearance with Vista. AMD is not incorrect to make their claims - there are lots of mATX boards being sold with 945 chipsets, and driver support for G965 is currently very spotty.
The same image quality difference comes up in a game like World of Warcraft, where SM 3.0 chips give you greatly improved views in and around water, because the surface transparancy is enabled. The 6150 manages ~20fps in WoW, but they're really pretty frames...
What about ATI's integrated chipsets? are those available for Intel as well as AMD, and do they support SM 3.0?