If you are too impatient to wait for Valve to release it’s own Steambox in the next half a decade or so then there isn’t much stopping you from getting a head start. Evan Rodgers over at The Verge has put together a great article on building one on the cheap! At a price point around $300 dollars it is very tempting to put one together.
It could be a great all around media center/gaming console not to mention a fully functional PC. I would assume when Steam does release their Steambox the software to run one will still be bundled into the desktop client. If you are interested in building your own Steambox just click the link below!