Linux gaming for the most part is non existent. There are a handful of games, but for all the bells and whistles that the gaming industry puts forth, not much of it makes it to Linux. Activision is a good exception to this, I’ve followed their gaming engines since Quake II in the late 90’s. It was with the release of Quake III, a fully native Linux version was available. A full featured FPS (first person shooter) that was a commercial release really showed off the potential of Linux gaming. Activision has designed their gaming engines such that ports to other operating systems (Linux, MacOS, Nintendo, etc.) should be much easier. Which is in their best interest money-wise — Licensing!!! Many games, Caste Wolfenstein, Elite Force and Doom 3 to name a few have all been released as such.
Quake 4 was released only 2 days ago (Oct 18) and the Linux installer is already available. The best thing about this deployment method is that if you buy the Windows version, the the Linux installer is available for download and uses the data files from your Quake 4 windows CD’s. Basically 2 for the price of one. Id Software and Activision really get a thumbs up for open minded design.
Now if only the rest of the gaming industry could follow suit. But for a incredibly small Linux gaming market and for the relatively higher development costs and minimal returns, I seriously doubt that Linux games will improve any where in near future.