You can't really say that linux will get 380 games as it would depend on the individual companies to port them.
For now I would say look at Valve's own Source Engine based games. Hopefully other companies follow suite.
I think Alexan's point is just because Steam is coming to Linux doesn't mean 100% of the library is too.
Of course, all of it remains to be seen, but I have confidence.
It looks like Microsoft Windows 8 is going to be much more secure by default than Microsoft Windows 7. It also looks like it will protect against attack vectors targeting the memory.
This all looks to be very tempting to me. I might just wind up upgrading for $39.99 USD on October 26th, 2012.
My point is a to have a rough statistics on how many game translate "Steam for Linux"
Game count for Apple is 380 titles and has ~6% of market share (let's call it drain interest from software house.
Let's suppose that Linux it's still at 1%... 1/6 worth for the software houses interest.
1/6 of 380 is 63 titles. Which is not a very promising base. But let's try to extend a bit with some potential Linux has to offer (why Linux could drain more interest in both Valve and other software houses)
1. No owner: Mac owner is Apple and Valve has to obbey to Apple's house rules. Windows owner is Microsoft and same rule apply. Plus both Apple and Microsoft suffer form "unfair" competition: soon both Apple and Microsoft will push for every pc sold their own market. Unfair field for another marketer like Valve
2. future of the platform Independence: you don't like what Trovalds is going to plug in the future kernel? Just do like Google with Android: fork it (or find alliance to do so). Your work is never lost if you've enough skill/development capabilities.
3. Costs license: 0, seriously... your clients hasn't to pay for their OS within each update (XP, Vista, Seven, 8... lion, leopard caturday&co). So where other user pay for update their OS, Linux user can just buy 3~4 more games. Yeah, that's a weak point, but still stand.
4. Make your own distro. Let's figure all those poor XP users that are still locked to Direct 9 perfomances. Now, imagine Valve make it's own distro exactly on propouse to run on dual boot: latest kernel, latest OpenGL, latest drivers only to run your game at full throttle.
IE: shutdown XP > reboot in linux in about ~30sec (only modules and stuff need for gaming) > launch game.
Thare are more points that actually doesn't come up in my mind
In rough "market share" statistic Linux has very low interest, but as the Ouya project show... interest is something that can be build in few weeks if you have a good idea.
Gabe Newell is also talking to other companies using steam as their delivery platform about their porting work for Linux. Maybe one or two of them bite.
Either way only time will tell what's gonna happen.
Apparently "Left 4 Dead" runs faster on Linux/OpenGL than Windows/Direct3d...
"That the Linux version runs faster than the Windows version (270.6) seems a little counter-intuitive, given the greater amount of time we have spent on the Windows version. However, it does speak to the underlying efficiency of the kernel and OpenGL."