realmaverick - 3:12 pm on Sep 12, 2013 (gmt 0)
While that would explain the increase in iOS devices, it wouldn't explain the big increase in traffic.
As this isn't being widely reported, I'm guessing we're part of a small beta test group. Most web masters won't monitor their traffic as closely as I do, and of those that do, it's likely they won't check the browser & OS, so the others that are part of this test group, likely haven't noticed.
I expect a roll out of this imminently.