Yeah I was gonna say this. I assumed the current client has 1920x1080 textures (even if ps3 only shows them at sub-720p, still) and the fact ps4 is only 1080p for gaming, why would they be getting higher res textures?
Well, that's not really how it works. the engine can handle textures of almost any size but they are generally square and powers of 2 (e.g. 1024x1024, 2048x2048, etc.) The resolution applied depends on the use of the texture. some pixelation on larger characters when you have very small ones is expected because the textures are being made from the same source art. BUt not only that, different textures applied to the same models may have different resolutions, depending on the level of detail needed. You don't want to use a higher resolution than is really necessary because that requires more memory. THIS is why the resoltution on some textures/materials is limited, for efficiency/performance reasons. Those factors don't go away just because a system supports DX11. The main benefit to DX10/11/12 is improved performance of certain effects and new graphical effects that don't exist in 9.0c.