The PS4 isn't going to out "power" even current gaming pcs. But because it's a closed system and devs can optimize games for it's hardware the games will look awesome. PC games have to be made to run on low end systems, high end systems and everything in-between. It's rare for a game to look the best if it was also designed to run on a PC from 5-8 years ago. It has been done, Crysis still looks great, but it's rare.
What's interesting about the next gen and how PCs will be effected is that most gaming engines have become multiplatform and highly scalable. 3rd party devs are going to be making less and less exclusive games. That means we are going to see even more games that look identical on PS4 and Nextbox as well as PC. 1st party PS4 and Nextbox games will take advantage of their system's strengths, but PC devs will be forced to continue to support older hardware out of fear of cutting out customers with less powerfully machines. Time will tell if scalability will let high end PCs beat consoles next gen or if old PC hardware will continue to hold back graphics to the lowest common denominator.
