Yes and no. It's got a 3.2 GHz tri-corePowerPC derivative w/SMT. so that's great, but not "more powerful than high-end PC"...Produce better graphics for a given game than PC? likely yes; due to it having a 500M/sec Polygon Performance as opposed to the XBox's mere 116.5M polygons/sec. Which, by the way, polygons mostly determine the "smoothness" of the shapes, as it's what the images are made up of, so a larger amount and faster fill-in rate means better-moving and better-looking. (not choppy, pointed graphics, i.e. square biceps)
The Xbox's Pixel-Fill-Rate is 3.7G/sec compared to 360's 16G/sec. The Box's Memory Bandwidth was only 6.4GB/sec while 360's is 22.4GB/sec...all of this will add up to superb graphics and accuracy (i.e. when sniping)
The normal console will cost $399...The base unit or "Core System" will be $299.