All your GNU/Linux folks, here is some bad news for you guys. Your work will have to take a back seat for a while as Steam has just announced Portal 2 for Steam for Linux client.
We have just made Portal 2 available in Beta form on Linux; to access it, you need to opt into the Beta from the Portal 2 properties in your Steam Library.
Since it’s a beta releases interested users will have to join the beta program. Also keep in mind that beta means pre-release or testing so there will be bugs and glitches and the reason Valve is making giving early access to the game so users can help find and fix bugs.