Apparently the work being done on the next iOS version is reaching its final stages. A recent 9to5 Mac report revealed that one app developer recently noted the "iOS6" string when collating the OS version from analytics software.
This could point to a June release, although reports on the matter are conflicted. Some say Apple will release iOS 6, codenamed Sundance, sometime around autumn.
It would make sense for the company to present the latest mobile OS and the long-rumoured sixth generation iPhone simultaneously. Irrespective of when the final product will reach the masses, there are already users who are enjoying the new "toy".
The first signs of the iOS 6 string appeared in late April, but iOS 6 usage seem to have intensified since. Apparently, Apple is testing the compatibility of the next iOS with various apps.
Apple's next iOS version is rumoured to replace the current Google Maps with a 3D mapping system, along with many other improvements and surprises.