Yeah, that's what I was thinking you were saying. However, with all these games tied in with DirectX, I highly doubt they will come to nix. They'd have to be custom-ported to nix, DX removed or coded into nix, which won't happen. Basically the whole game would have to be re-written for a very small audience. Not saying it can't happen, just saying that the odds of it coming to light are very slim at this point in time.
I'm still kinda confused as to why they are making the client available on OSX, because the amount of Mac compatible games is relatively small.
Valve's own site wrote:
Also: How dare you! Mac users aren't getting a crappy emulated version of the game. TF2 will run natively on OSX, like an actual big boy game for adults.
That implies OpenGL, which Linux supports. But, then again, if you just read the thread first, you'd have already seen that.
But anyway, I'd say Dwood's right. Firstly, it's not all games, just Valve games, since they all use a similar engine, so porting one game is the hurdle, the rest can just follow quickly. So if they're making it OSX compatible, linux, like I said, shouldn't be some far-off dream at that point.