Apple has released information on the security updates that were covered in the recent release of iOS 5.1.1. When it was originally released yesterday, all that we knew was that there were various bug fixes. This update actually covers some important security fixes too for Mobile Safari and WebKit based browsers in general.
If you do a lot of web surfing on your iOS device it is definitely worthwhile upgrading to iOS 5.1.1 just for these security updates. Of course if you are running a jailbroken device you will want to still clear for now.
Given that, with iOS 5, Apple introduced over-the-air (OTA) updates to the iPhone, iPod touch, and iPad, it's interesting that they're still waiting and bundling security patches into larger software updates. OTA updates are done via bit-differential (delta file), and happen on-device and without the need to backup, re-install, and restore, so they're small and incredibly efficient. Apple could choose to push out security updates far more frequently. It's possible they think more frequent updates could annoy users, or their numbers tell them too many users are still updating over USB with iTunes for it to make sense right now. Hopefully, however, they're moving in that direction.
If you haven't yet updated to iOS 5.1.1 and you're looking f, here’s where to go: