I know power is the only real measure of a console when we have so few details (not to mention the 'wow' moments that companies strive for) but I can't think of a generation of consoles in which the most powerful sold the most. Sega Genesis, Neo Geo, 3DO, N64, Xbox, PS3(arguably) - If anything, logic would dictate that companies like Sony and Microsoft should actually avoid being the more powerful next gen, because they always sell less that a console either with a well stocked 3rd party library, or that pushes into a new play style.
I'm not by any means saying that 'powerful consoles are bad consoles' - just that they don't seem to sell as well, and that I'm a bit puzzled by this fixation of visuals, especially when it's getting the to point of having to go over every tech demo to see which direction a demon's pubic hair is pointing.