EA isn't the only publisher clashing with Valve's current policies. At this year's PAX, Minecraft creator Notch was asked why Minecraft wasn't available, and while he took plenty of time to praise the platform , has explained that it's just not a fit for what he wants for the community going forwards.
"Being on Steam limits a lot of what we're allowed to do with the game, and how we're allowed to talk to our users," he explains. "We (probably?) wouldn't be able to, say, sell capes or have a map market place on minecraft.net that works with Steam customers in a way that keeps Valve happy. It would effectively split the Minecraft community into two parts, where only some of the players can access all of the weird content we want to add to the game."
The word 'probably' is important there, and he goes on to say that Mojang is talking with Valve to see if there's any way to make it happen. If not though, it won't just be EA games not putting in an appearance due to DLC and item store content. Will Valve be prepared to sacrifice their piece of the after-sales pie in the game of getting hot games on their platform, or will developers and publishers have to bite the bullet and cut them in? Let's hope they come up with a good answer before too many games go AWOL.