I dont know about you guys, but I dont measure the value of a console by its horsepower, but rather by its "fun factor". Now I havent played the Wii nor the PS3 yet, but judging by the impressions given by people who tried the Wii at E3, Wii should really be fun playing and giving a totally new experience, while the PS3 offered the "same ol' stuff we've been playing since 1996"
At this point i'd rather give 400€ for the Wii rather than the PS3.