In my State of Drupal keynote in Chicago I said:
If I were to start Drupal from scratch today, I'd build it for mobile experiences first, and desktop experience second.. I believe in that more than ever.
We already have a number of initiatives under way that will make Drupal a great platform for building native mobile applications (e.g. the Web services initiative) as well for building mobile web experiences (e.g. the HTML5 initiative and the Design initiative).
However, there is more that needs to be done to make Drupal a go to platform in a mobile world. For example, a couple of weeks ago I talked to a number of big media companies, each employing hundreds of editorial staff. They all believed that in less than two years, most of their editors that report from the field will be using tablets instead of laptops. Applied to Drupal, this means we need to make the Drupal administration back-end and the editorial experience mobile-friendly, something that isn't covered by the existing Drupal 8 initiatives. Another example would be responsive web design.
The mobile internet is coming at us fast and furious. We need to move fast and we might only get one shot at this. I want to make mobile the big theme for Drupal 8. That is why I decided to launch another initiative related to mobile.
I've asked John Albin Wilkins to be the Initiative Owner for the Drupal 8 Mobile Initiative, and to work with the existing initiatives to fill the remaining gaps. To learn what that means, please consult John's announcement blog post, which includes an overview of the initiatives' goals. Like with any of these initiatives, they don't actually materialize unless people decide to help. To get involved, please join the discussions in the Mobile group on groups.drupal.org and help work on Mobile issues on drupal.org.
— Dries Buytaert