The question isn't whether happy touch-gamers would buy these controller cases in bulk. The question is: should these cases exist and get developer support, how many 3DS and Vita gamers would continue paying a premium for their dedicated devices and software libraries?
Android and iOS already "have" the larger slice of the market. (The "touch gaming" slice) My point is that they're a very short step away from essentially taking "all" of it. (Not literally all -- focused devices may still live on -- but enough that Sony and Nintendo's current model can't sustain itself.)
Also, I think you're "off" on the size estimate.
Extend a hypothetical mobi-style battery case an inch-and-a-half on the 'head' and 'chin' of an iPhone. D-pad on the left, some buttons on the right -- maybe even shoulder buttons if you're feeling saucy.
The result is still pocketable and smaller than a Vita or 3DS. (Similarly for any number of popular Android phones -- though phones with 5" screens would push the arrangement directly into Vita-ish dimensions.)
Stand-alone controllers are an important part, but they'd be something that provides consistency on the TV-screen side, with things like GameStick, Ouya and/or Apple's rumored AppleTV gamepad play.
Android and iOS already "have" the larger slice of the market. (The "touch gaming" slice) My point is that they're a very short step away from essentially taking "all" of it. (Not literally all -- focused devices may still live on -- but enough that Sony and Nintendo's current model can't sustain itself.)
Also, I think you're "off" on the size estimate.
Extend a hypothetical mobi-style battery case an inch-and-a-half on the 'head' and 'chin' of an iPhone. D-pad on the left, some buttons on the right -- maybe even shoulder buttons if you're feeling saucy.
The result is still pocketable and smaller than a Vita or 3DS. (Similarly for any number of popular Android phones -- though phones with 5" screens would push the arrangement directly into Vita-ish dimensions.)
Stand-alone controllers are an important part, but they'd be something that provides consistency on the TV-screen side, with things like GameStick, Ouya and/or Apple's rumored AppleTV gamepad play.