DirectX 12 Client

[ReiszRie]

From what I have read DX12 is basically DX11 with mantle baked in. Some improvements over 11, but not radically different. Because of this, all DX11 cards are capable of running with DX12. Fermi, Kepler and Maxwell (Nvidia 500 series forward) will be called DX12 ready cards. Since DX11 is on Win7, there is no reason DX12 can't be moved to Win7, but MS does want to push dat Windows H8 point done.

Unlikely, Mantle is a technology from AMD that seeks to replace DirectX by allowing games to directly communicate with the GPU without passing through another layer, DirectX 12 was created in response to Mantle and as such, you can expect it to take a long while, even till now, there has been little information what advantages and improvements DirectX 12 brings to the table and how it would compare with Mantle which has shown to significantly increase performance

[Zumi]

dx 12 will most likely be windows 9 only which not everyone is going to buy. MS usually forces people to upgrade OS to get the latest direct x. Personally I stuck with 7 and I didn't buy 8 because the tablet panels on a desktop didn't seem like a feature I needed.

[Nekodar]

Unlikely, Mantle is a technology from AMD that seeks to replace DirectX by allowing games to directly communicate with the GPU without passing through another layer, DirectX 12 was created in response to Mantle and as such, you can expect it to take a long while, even till now, there has been little information what advantages and improvements DirectX 12 brings to the table and how it would compare with Mantle which has shown to significantly increase performance

Work on Direct X 12 started 4 years ago according to nVidia.
It's more likely AMD decided to take ideas from the work they were privy to and make their own API for marketing reasons.

[klepp0906]

We already know DirectX 11 FFXIV client has been delayed till after expansion from February interview with Gamer Escape. So it's likely be available in 2015 at the earliest.

Microsoft just released details of DirectX 12 and it's quite possible for SE make a Directx 12 client instead. DirectX 12 should be much more beneficial to FFXIV with "Multi-thread scaling + 50% better CPU utilization". I expect this to allow higher character limit and higher FPS in high populated areas. Unlike previous Directx versions DirectX 12 should work with over 80% of gamer PCs currently being sold.

Source: DirectX Developer Blog

They don't deem dx11 client worthy and your asking about dx12? Don't expect to see this, ever.