The problem with your question is that they all have differences. How do you define power?
Mhz?
Polygons per sec?
Memory?
Textures?
Each console will win in some areas and lose in others, no one dominates the range of important criteria. If you try and make an "overall" rating for the system, you get into things way to complicated to figure out. Different types of RAM, ease of programming, effects, output to screen quality .... to much stuff to make an "overall" judgement.
Power at this point doesn\'t even matter that much. These consoles are all capable of producing graphically spectacular games. It will come down to gameplay, stories, characters, and so forth with this generation.