That does seem surprisingly low, but let's assume it is that correct.
According to stat counter , mobile usage in Jan 2010 was 1.56%, by Dec 2010 it was 4.1%. By Feb 2012 8.53%.
That's an astonishing growth to have roughly doubled in a year. Although the growth proportionally is less than in 2010 which might suggest that there is some slow down.
Big companies like adobe need to plan for the long term, even if "mobile" peaks at 30% + all the people running Windows 8 using Metro + all the Linux users.
That's certainly a big enough base of non-flashers for any web developer to seriously think twice about using it for anything.
"Web usage", as a percentage, usually means "site visits", not "web users" or "devices".
Most people do not own tablets, outside of pretty narrow demographics. Most people who have a smartphone do way less browsing on it, by number of site visits, than they do on their computer.
