yup exactly, another important factor is that the main RAM this time has a huge bandwidth in consoles (GDDR5) compared to PCs (DDR3), games designed for this specific ps4 feature would have a hard time running on any PC even with 16 Gb of DDR4.
people here are downplaying and underestimating how much of a difference this would make for porting ps4 games to PCs. lets give an example :
a hypothetical naughty dog game called uncharted 4 running at 30 fps and sending 3.5 Gb of data per frame per second to the SOC CPU+GPU to handle (high rez textures, polygons, instructions, shaders, models, animations...whatever) how are you gonna make that run on a 1-2 Gb per frame limited RAM (DDR3-4) on PCs ? it is of course feasible with the help of compression and using the huge amount of main RAM and the very fast GPU RAM of very high end PCs as caches, but it is impossible to do this correctly on a mid-range PC of 2013-2014. And developers wont take the risk creating a game thats possible to run only on very high end PCs.
Thats the kind of situation PC games would face compared to exclusive PS4 games...in short, if the recent rumors of PS4 specifications are true than PS4 exclusive games would do some crazy things impossible to do with commercial PC games for at least the first 1-2 years of the console lifetime. More precisely I am thinking of very high rez textures all over the place (2048*2048) or some very fast complex and detailed gaming scenes running at crazy 60 fps a la Gran Turismo...etc