As you say, there are and will not be any consoles capable of rendering games natively in 4k resolution any time soon, at least not until the next generation of consoles, if not more, in fact they seem to be scaling back the promise of 1080p native res on both consoles now.
As for the ps4's 4k support I would guess it will be on a similar level as the ps3 now supports 3d blue ray, inow enough for a taste but if you really want it you would be better off with a dedicated player.
If they are demoing say, the ps4 on a 4k panel then it will be upscaled internally and any type of such upscaling will induce a level of input lag that would be quite detrimental to any games that rely on quick response times, in short rubbish marketing gimmicks.
At best these consoles will look and work just as well on 4k panels as they do on 1080p, but this requires a game mode with almost none of the image processing that makes 4k panels 'worth-it' I personally don't think they are yet but that's me.
Simply put, as per the norm, first time we will be able to do real 4k gaming on these screens will be from a pretty hefty computer with HDMI 2.0 outputs and the next gen 4k panel tv's also featuring HDMI 2.0 .
If you can't wait for that you would have to use a 4k monitor with display ports