The quote was "It's about as powerful as the original Xbox," he said. "The video hardware unfortunately is not as powerful. There's just a couple of key things that you can do on Xbox like shaders which you just cannot do on the Wii... Overall though it's pretty much what the original Xbox was." which is (pretty much) exactly what people said about the Gamecube.
I (personally) believe that what many people miss is the Gamecube was never designed to be very powerful in terms of programmable hardware on the GPU (shaders) and was (instead) focused more on producing games that involved "high polygon counts" and highly detailed textures. The Wii just takes this to the next level. The overall result is that in many ways it is still not as powerful as the XBox but (if the game is designed specifically for the Wii) you will still see games which look better than anything on the XBox.
To understand how the Wii has improved over the original Gamecube (which was reported to be "about as powerful as the original Xbox," ):











