http://www.rockpapershotgun.com/
Certain elements of the image they got, like the little dots at the bottom, scream Apple. Will Steam be coming to Mac?

This is what they sent to Kotaku:
http://kotaku.com/5484948/valve-teases-upcoming-mac-announcement-not-so-subtly
HOLY SHIT! It is coming! This will be bigger than big. Steam will be everywhere! WORLD DOMINATION!

Cool, I've been hoping they'd put it on Mac so I could use it with my Macbook Pro. While I know that my PC games will never be playable on the Mac without rebuying a Mac version (if available) it is nice to see the two platforms cooperating.

So Mac players will join the fray on Steam forums (there were many PC vs. consoles wars, IIRC)...does it mean that we are close to ultimate flamewars with lots of trolls?

This will no doubt please a lot of people. Plus, if games development for Mac increases then it will undoubtedly have a knock on effect to PC gaming too. At a time when it really could use the boost.

We can only hope.

I can't help it but most Mac users annoy the hell out of me.

*crosses fingers for Linux too*

Pah, dream on, your platform will never be good for anything but servers and hobbyists.
</sarcasm>

I just love the way they did the Mac ads, especially the ones based off of the iPod.

and thus the dark age of PC gaming began with $60 games, mac gamers, and A PERMANENT INTERNET CONNECTION AND CREATION OF A UBISOFT ACCOUNT ARE REQUIRED TO PLAY THIS VIDEO GAME AT ALL TIMES.
http://store.steampowered.com/app/481

Apple would do that if they could, but that only happens on the iPhone, iPod Touch and iPad.

On that note, most female Mac users I know are hot lol

Don't worry. They'll learn their lesson when sales are piss-poor.
Yet another image, this one sent to MacWorld, with Alyx reenacting that 1984 commercial where that woman runs up to that propaganda screen and throws something at it.
http://www.macworld.com/article/146840/2010/03/valve_mac.html