Problem is that in this generation and certainly the next, developers will be willing to sacrifice resolution and/or frame rate in order to put out better graphics. When your average console is hooked up to a 40" HDTV set 7-8 feet away, running a game at 1080p isn't as much a priority as it is on a PC monitor where you strongly have the 1:1 pixel ratio effect. My proof of this is that the average person who owns both a 360 and PS3 probably won't be aware that the homescreen is 720p on the 360 but 1080p on the PS3 (and that's with text where its super easy to notice).
This is certainly true. I was always aware of the UI difference between the two, as the X360 interface always looked "fuzzy" next to the PS3 interface (I used to have both systems, I sold my Xbox a few months ago).
Unfortunately, I am one of the ones who can see the difference. Not so much with video content (1080p is just slightly sharper, but 720p doesn't look bad by any stretch), but definitely with aliased game content. Then again, I have a 60" TV viewed from about ten feet. 720p games look good, nice and sharp, but the pixels are definitely noticeable to me. 1080p is pretty much flawless, and you can get away with a much more meager AA solution, I think, since the individual pixels are much harder to see anyway.
As for PS4, the only one we know for sure about is Killzone, running at 1080p. I hope other developers follow suit, and finally give us the "True HD" gaming they promised us seven years ago.
Another big factor for me is 3D support. That big 3D TV of mine is only about a month old, and it was very disconcerting that Sony appears to be dumping 3D, or at least not pushing it on PS4 as much as they did with PS3, and they're leaving it up to the developers as to whether to support the feature or not.
The reason I bring it up is because I also have a 3D monitor on my PC, and there are games I can play there in 3D that don't support 3D on the Playstation. That alone could be a deciding factor when choosing which version of a game to get, if it's one that I think could benefit greatly from 3D, and if the support for that game is much stronger on PC than it is on console. For example, the upcoming
Tomb Raider game, which I'm still on the fence about. I'm leaning more toward PC partially because of what appears to be proper PC support, as well as the very likely chance that it will work very well with 3D Vision, while the console versions don't appear to support 3D at all. That's one thing I'm actually waiting to find out in the next couple of weeks, is how well the game works in 3D on PC.