If they want to reach a billion people then they're going to have to live in a world of touch screen (and maybe voice).
At NDC Oslo this year there was a keynote by Luke Wroblewski on user experience on the web. There's a video on Vimeo: http://vimeo.com/97305189
The key takeaway was that a significant percentage of people are using their smart phones with either only their thumb or their forefinger. Many people don't even have a computing device with a traditional keyboard and full-size screen. That talk got me thinking about this question: what would programming look like if you only use your thumb?
I don't think you can write off these interfaces, rather I think we may need to start to really think about separating creation of core components of software and then orchestrating the interaction of these components as a different aspect to developing software.