>> Valve is clearly working on -something- for steam on X86 Linux.
No. They're not.
Someone there did obviously set up their build system to partially build a Linux (32-bit only) client. However, in all the time it was available, it never showed any progress. The only time the included files changed is when Valve updated common files for the Mac client. You couldn't even get it to start up without hacks, and the GUI was broken as hell.
The official word from Doug Lombardi, whose job it would be to market Steam to us, says: "There's no Linux version that we're working on right now."
Don't get me wrong: I've used Linux as my primary desktop for the last six years, use Steam under Wine to play all my games, and would *love* to have native versions instead. There's just no reason to believe that they're doing any work on the Linux version at this point, or ever going to release anything for us.
So to get back to the original poster's question: If Valve doesn't think there's enough money in porting Steam/Source to the millions of Linux users, there's no way in hell there would be a Pandora-specific release.