Some XBox 360 fans reported that PS3's RSX GPU was not as powerful as the current GeForce 7800 GTX based cards. Well this is not true. The source of all the controversy was a misquote from an issue of PSM magazine. The website that originally sourced this news misquoted it and stated that the 7800 GTX was slightly more powerful than the RSX.
Here is the correct statement from NVIDIA:
"RSX way better than Geforce 7800 GTX" - 05.04.06