Thing is with resolutions you say 4k is the future but why not 8k which is already on the horizon? It's all well and good having more pixels and reducing the need for AA but it doesn't add much if any immersion. To really progress they need to add things that make you feel you're in a totally realistic environment.
I have to agree with Orangey as well, splitting the market up where you need both sides hardware to get the most out of certain games is going to be terrible but I guess both sides are too stubborn to avoid this so it's looking inevitable.
It's called baby steps, atm there is no single chip card that can max out 4k @ultra so we need to have the next generation of cards to be able to do that before we even start thinking of going even further!