"Yesterday we showed proof of Steam's Linux client existence via
its Mac OS X launcher that is currently in closed beta, then this
morning we showed further signs of Linux support. Since 2008 we
have known that Steam and the Source Engine would come to Linux. As
an update, we even pointed out the download link for the Steam
Linux binary from their store.
"If you go to this file there are references to all the
components you need for the Steam Linux client (as also pointed out
in this forum post). They can then be extracted and assembled
by-hand by following the same layout as the Mac OS X Steam client.
You can then proceed to launch the Linux-native Steam client, but
it will have problems connecting to the authentication/update
server (but that can be worked around)."