I agree the evolution of mobile will be basically a console. In fact, I said in my original post that the next popular consoles will run iOS/Android. And these tablets without the screen already exist. They're called Google TV and Apple TV (tho Apple TV would still need app store). Put more power, a controller, a game friendly UI and you got a real console competitor. Expect that to happen, at most by 2013.
Mobile does have big advantages over console, just as these had over arcade. A) The ecosystem lock is huge. Having all your existing apps, games and settings, instantly transfer seamlessly to your living room is something current consoles cannot reproduce (yet, tho msft is working on it). B) they're mobile after all. Playing an AAA game on your living room is nice, but what about when you're out? You can bring your tablet with you.
I agree with you that the real issue for steam is whether current stores are gonna need them. Unfortunately for them, I don't think they got much leverage in this negotiation. They don't have any games that work on iOS, Android or WP. Even if they partner with MS (whose got a week ecosystem right now). The combination of both of them would still be weak compared to iOS and Android. I honestly don't know what they could do. They'd have to pull off something brilliant. But choosing to work on linux this late in the game, gives me a hint they might be out of brilliant ideas.
If you are talking about something that is basically a set top box like apple/google TV then I'm not sure it fits the definition of "mobile" just because it runs android/iOS.
It is possible that Apple/Google could try to muscle in on gaming. I could imagine this to a certain extent with Apple but with Google it would seem to a huge swing from their core competencies and I think they are spread thinly enough as it is. It would be more realistic for Sony to announce that the PS4 would be an android device with a Sony UI and games running on top (probably + a load of proprietary APIs so you couldn't just install your games on a competitors device).
Another advantage that console games have is that they have to go through a brutal QA/Acceptance cycle before they are allowed to be released for the console. If you dig through play store game reviews you will see huge numbers of 1 star reviews because people found the games to be buggy.
In terms of having something that can transfer your apps/games/settings, Steam pretty much already does this (although in terms of instant you are throttled by bandwidth on that one). I'm sure the next gen consoles will have this functionality too and most purchases of games will be made online.
There is a case to be made for gaming when out and about but this is quite a different experience to actually sitting down for games therefor the games are likely to be different and have different input methods etc. When you are out and about there is fair chance that you are either: driving, working or doing some other activity. If you wanted to play games you would stay at home, the times when mobile games are useful is for killing short waiting times or for the occasional flight/train ride. So what you want in that case is short fun games like angry birds rather than AAA epics. This suggest there will be 2 markets for mobile and non-mobile games, in the same way that the gameboy was popular at the same time that the SNES etc were, it does not suggest one will kill the other.
Also when you have a system and games designed to run off mains power and without the same constraints for weight etc you can have much more beefy hardware and create a different level of experience.
As it is my android phone burns battery running even relatively simple games.
I imagine the Steam for Linux is part of a bigger play, either trying to get in on Android or a precursor to launching their own hardware. Either that or they just want to show MS that they have other options.
Mobile does have big advantages over console, just as these had over arcade. A) The ecosystem lock is huge. Having all your existing apps, games and settings, instantly transfer seamlessly to your living room is something current consoles cannot reproduce (yet, tho msft is working on it). B) they're mobile after all. Playing an AAA game on your living room is nice, but what about when you're out? You can bring your tablet with you.
I agree with you that the real issue for steam is whether current stores are gonna need them. Unfortunately for them, I don't think they got much leverage in this negotiation. They don't have any games that work on iOS, Android or WP. Even if they partner with MS (whose got a week ecosystem right now). The combination of both of them would still be weak compared to iOS and Android. I honestly don't know what they could do. They'd have to pull off something brilliant. But choosing to work on linux this late in the game, gives me a hint they might be out of brilliant ideas.