To make holiday shopping a bit easier and to make sense of the
seemingly unending number of hardware revisions that have been
released in the last two years, we have put together a handy chart
detailing the different Playstation 3 models released in North
America. It's interesting to see how the PS3 has changed over the last
few years, as dies are shrunk, and more features are ripped from the
hardware in each revision.

http://www.hardcoreware.net/playstation-3-model-guide/

It also includes a Playstation 2 backwards Compatibility chart, so you
can be 100% certain that you most likely will not be able to play PS2
games on your shiny new console.

Thanks!