But I don't think they count iPads and other tablets as "mobile." Their Mobile Browser chart listed iPhone and iPod touch separately and didn't list iPads at all. Mobile Screen Resolutions doesn't include iPad resolutions. Browser Versions (Partially Combined) has a separate entry just for Safari iPad (which actually exceeds Safari 6.0 and Safari 5.1, combined).
http://en.wikipedia.org/wiki/Usage_share_of_web_browsers
Here is StatCounter for Mobile for the last 6 months, the iPhone browser with 23%: http://gs.statcounter.com/#mobile_browser-ww-monthly-201207-...