According to ad network Chitika, iOS 6.1.2 — an Exchange bug fixing update — is the most popular version of iOS just a week after its release. In fact, the most recent major version, iOS 6, comprises 85% of all versions of iOS in the wild.
Meanwhile on Android, the latest version — 4.1 and 4.2 Jelly Bean — sits at 16.5% of all Android users. In fact, all of Android 4.x installations represent just 45.1% of all users, only slightly edging out Gingerbread at 44.1%, which is now well over two years old.
Update: David Smith is seeing nearly 87% of users on iOS 6.x.