Now I've read IGN claimed to have heart from an annonymous studio current Revolution development kits are just slightly faster/better than the xbox hardware. This is funny, because this is both true and fake.
Why you ask?
Two months ago our studio aswell was still working with a Revolution development kit that had slightly more power than the current xbox. Less than a month ago however, we've again received upgraded development kits. Now I suspect ( no I'm actually positive ) this studio talked with IGN just before Nintendo handed over new development kits. It's also posible by the way, as I'm not sure how big this annonymous studio is, hasn't received the upgraded development kits as of yet. Mostly of the time the "big" studio's receive upgraded development kits a few weeks before the small ones do, because it's not a cheap job to replace development kits every time.
The most up to date working Revolution development kit has alot more power than the previous one. I can even confirm to you the newest development kits are the first development kits that includes prototypes of both Hollywood and Broadway. The previous versions didn't have those included.
Now if you look at the current specs of both Hollywood and Broadway ( which I will not provide to you, so do not ask ), we're not talking about a slightly upgraded xbox, but pretty powerfull hardware. Revolution's power is not underpowered compared to xbox 360. I can't speak for Playstation 3, because I've no acces so any stuff involved to Playstation 3 development.
However, Xbox 360 has more power than Revolution, but Revolution isn't underpowered.