As a Dolphin user with an AMD graphics card, I'd love to see this happen. I can see why there wouldn't be any plans to do it, though. It would require pretty extensive code work, and it would only benefit users with AMD cards. That said, it's an open API, so that could change if nVidia decides to add support for it in the future.
There aren't any plans to support it.
Also it may be a "open" API, but it still isn't publicly disclosed, so we couldn't implement it right now even if we wanted to.
Didn't delroth/neobrain say it might be an easier way to get accurate hardware acceleration than DX/OGL? I thought it was at least a 'we might look into it eventually'.
Got a quote? I remember neobrain saying the opposite, but I could be wrong.
I can imagine that Mantle will give you a lot of control over the rendering pipeline, thus allowing Dolphin a lot of flexibility in what it can do without incurring a massive slowdown, but I'm not qualified enough to have an opinion on that since I don't know shit about writing a 3D renderer.
Besides my crackpot speculation, I'll leave you with the only Mantle-related quote I have:
<pauldachz> IIRC, neobrain later said that he's probably not gonna bother supporting Mantle, so don't bother getting your hopes up about that.
<neobrain> mantle is useless
<pauldachz> ^
It was something like 'Imagine emulating GCN on GCN directly' or something. At least I think so. This may all be rubbish.
Ah! I have that one.
<delroth> I don't care about what it does, I just want to be able to say "we emulate GCN on GCN".