Valve is thinking about the advantages of bringing Steam-related features to mobile platforms.
Valve is a juggernaut in the games development space with titles such as the recent Portal 2, and in digital distribution with Steam, but has been conspicuously absent from the booming mobile market. While certain members of the company find the market "interesting," Valve is still just "looking at" how it can integrate itself onto mobile platforms.
"We do feel we're late on mobiles across many of Valve's services," Valve VP of marketing Doug Lombardi told Develop. "It's something we're starting to look at now. There's a common set of [Steam] features that people could see themselves using, and are starting to ask us for."
Lombardi is presumably referring to features that would require users to connect to their Steam accounts through a mobile-specific interface. Lombardi added that the more requests Valve gets, the more likely it'll be to implement this ability. However, in my view an entire mobile Steam storefront seems like it might be impossible without a "Valve Phone" or a Valve mobile OS - two herculean projects - considering how Apple, Google, and the rest of the mobile bunch regulate content (no storefronts allowed).
As for Source Engine games, built using Valve's trademark technology, we may not see them in the palms of our hands for a good while (if at all). "If people want people to build a mobile engine today, call [Epic Games CEO] Tim Sweeney," Valve boss Gabe Newell said, referring to Epic's mobile version of the Unreal Engine that has resulted in games such as Infinity Blade. This comment makes it clear that a full mobile market expansion isn't in Valve's cards for now, but look for the company to possibly test the waters as the industry keeps growing.