From the looks of things, it's pretty clear that both devices kick ass big time. From a pure processing standpoint, the PS3 appears to beat the Xbox 360, but a final determination will have to wait on actual hardware tests are done (3.2 GHz PowerPC with 3 dual-threaded processor cores---for the 360 and 3.2 GHz Cell processor with 7 single-threaded synergistic processing units cores--for the PS3). The PS3 has a few other advantages. It's completely compatible with all of the existing PlayStation 1&2 titles, which is a huge plus. And its video display capabilities outstrip those of the Xbox 360, with support for true 1080p displays. Dual 1080p displays. Wow. As for the GPU, oooo, it's up for grabs there. 360 uses ATi while PS3 involves nVidia with the 360 having more graphics RAM, but the PS3 has a higher overall clock speed and memory bandwidth despite the 360 getting like 512MB of GDDR3 RAM.
Xbox 360, however, drops the bomb on the PS3 in a few categories as well. It's HD Media Center Extender experience will blow away anything Sony can dredge up for digital media, and will support live and recorded HDTV over your home network. Its device connectivity--including direct support for Apple iPod and Sony PSP devices--is top notch. And the hugely compelling Xbox Live service gets even better with Xbox 360. Sony has nothing like it.