Although it is likely to simply be a small maintenance upgrade, it looks like Apple's latest iOS update may be coming next week. The update is iOS 8.1.3, and it will simply offer tiny "under the hood" bug fixes and performance improvements.
This intel was gleaned by the large number of devices recently found running a version of iOS with the number 8.1.3 on Apple's network. More than likely this is Apple employees testing out the bug fixes. To be clear, Apple's next "major" update will be iOS 8.2, so this one is simply a minor blip on the road to the larger update. We will keep you apprised if more info arrives.