Well BF4 launches with DX11, Mantle will be patched in later

Personally i think developers will go/stick with opengl.. Especially with now that OpenGL is in the all important tablet and mobile market catching up to good 360/PS3 level of graphics and the potential sales there..

They had me at "Yay!"

Initial releases will support multiple API's much akin to Unreal Tournament 1 where you selected which API you wanted to use.

Besides, technology will keep improving, by the time the next next generation consoles launch, launch games would be like minesweeper on a modern PC, making what-ever wrapper performance decreases, really a non-issue.
Plus, Mantle is open source, Glide wasn't and Glide was still reverse engineered. Generally Open-Source stuff will be fixed up if forgotten by a developer if there is even a small demand for it, lots of smart chaps in the world!

If you don't like the idea though, vote with your wallet! That is your god-given right as a consumer. :)

Emerging from lurking mode for a second to make a few points about Mantle.

Mantle is the direct result of a number of AAA game developers asking us for something like this because of several constraints they're experiencing with existing PC graphics APIs. Those developers want to get closer to the metal and able to achieve more with the GPU(s) on their PC without the API getting in the way of this effort. "More with more" is the term used by Raja and it couldn't be more spot on.
AMD listened to developer feedback and entered this venture with Johan Andersson leading the charge. Johan has a passion for writing efficient code that can allow him to accomplish his technical vision and Mantle exists to serve this purpose.

Mantle is not for every developer. It is a low-level graphics API designed to drive the GPU in the most efficient manner. This level of access requires a bit more development effort than existing APIs to reap the rewards it provides.

AMD remains committed to support DirectX and OpenGL and to keep optimizing our drivers for those APIs. Mantle is an option that some developers may choose, but it does not affect those that wish to keep using existing APIs.

Some technical concerns are mentioned on this thread. The Mantle API has been in design and development for more than 2 years and rest assured we've had some time to think about the best way to address those (and loads of others).

More technical details about Mantle will be revealed in due course. Johan is a keynote speaker at the AMD Developer Summit (11-14 November, San Jose).

Nick - Gaming Engineering Manager, AMD

http://forum.beyond3d.com/showpost.php?p=1788711&postcount=210

Did some more reading and digging around!
I honestly can't wait for November to arrive! If Mantle turns out to really be essentially a port of the low-level API that's on the consoles... And developers do indeed support it... Consoles will no longer have any performance advantages for any given piece of hardware, at all.
Thus the Playstation 4's underclocked Radeon 7870 will perform like an underclocked PC's Radeon 7870.

Essentially AMD could have potentially made high-end PC gaming cheaper for absolutely everyone if it takes off.

This means great things for me as a Radeon user. :P

But only for select few games

all the slides from the presentation can be found here
http://www.slideshare.net/DICEStudio/battlefield-4-frostbite-3-mantle

Idk, personally I have always had headaches with AMD/ATI cards, mainly bc of catalyst being such a pain in the ass. I have tried 2 times, and bought high end $350 cards and then to have one issue after another and ending up returning it and getting a nvidia and having no issues at all. Next time I upgrade, I will try for a 3rd time as a last chance. Maybe in 2 or so years it will be better.

The green team also has other things to worry about such as tressfx and advanced lighting. If devs start implimenting these things left and right it will get real ugly.