This is the huge benefit with the console wins to AMD that Carmack spoke about at Quakecon this year. Sounds like thanks to the new consoles, this will put AMD in the driver's seat. Everyone else will be stuck on DX or OGL. If NV/Intel implements Mantle it may well require a hardware change, since AMD defines this API going forward.
Or maybe it won't - it could just be implemented by firmware. If the computing power is there on the silicone some talented engineers could always find ways to use it. And this is not without benefits for nVidia - they could obsolete old 5xx cards that still got year or two life in them left.
And if the benefits of the api are so great as claimed than performance could go so high that for 1080p it will just don't matter if nVidia is slightly slower.
It is funny that Valve and AMD do for PC gaming what I claimed in 2001-2 MS should do - I called it game mode then. Unload everything but the TCP/IP stack and give all the resources to a game.
