No there isn't. Valve have never announced that they are working on a Linux client.

http://www.muylinux.com/2010/05/12/ya-es-oficial-¡steam-estara-disponible-en-linux

its on spanish but looks oficial for me

1. The link is dead.

2. There is nothing official about some article on a Linux website.

Steam for linux is coming it seems.

http://www.tomshardware.com/news/steam-source-engine-linux-mac-half-life,10412.html

http://www.phoronix.com/scan.php?page=article&item=valve_steam_announcement&num=1

the second link is toms source

You seriously trust an article on Phoronix with the reputation they have?

"It's Official: Valve Releasing Steam, Source Engine For Linux!" There is nothing official about that article whatsoever. They are claiming that Valve is creating Steam for Linux on Valve's behalf which they have no right to do.

Official = A statement from Gabe Newell or Doug Lombardi.

I do not know of phoronix, but I do trust tomshardware. It also just makes sense that they would be working on one, why would they not? The more pc's they have access to the more possible sales they can get.