It's not that simple. In some regards it's no more powerful than the Xbox 360, in others it's far more dynamic.
Would you as a developer spend three times longer in development and three times the money, to get a mind-blowing game that only sells the same as a Xbox 360 game? The 360 has been around for 16 months longer and there's still plenty of catch up to do to ensure that the PS3 has an independent demographic strong enough to support overly technical projects. It's common sense. Why are people acting like the PS3's strongest points are going to be revealed NOW, right this minute?
If you are not aware of it's cell processors capabilities or aware of the 7 SPU's (Separate Processing Units) and why they are going to prove useful in the future then the key might lie in readin some of the earlier pages of this thread or Playstation 3's wikipedia entry:
http://en.wikipedia.org/wiki/PlayStation_3
The reason why I want someone else to answer the question you've asked is that I've done dozens of hours of product research on the Playstation 3 and spent large chunks of my spare time informing others in this threads for months. The question you have asked is easy to ask in a few words, but the answer is so much more involved and requires a long, long answer.
I suspect you are keen on Xbox 360 and that's fine, but I'm weary now from my long slog with trying to inform people of the benefits of the PS3. It's not like I get much rep for it like the big NH guns do for some quick quip or a well placed smilie. It's simply not worth the effort.
All I can say is they are both great machines with strong points. Weigh them up and decide.
I just read esoj's post. Thank the lord, someone else intelligent to answer questions rather than pose them. Please esoj, take the wheel!!!!!!!!!!!!