Two days ago, Unity technologies has clarified several doubts about the 64-bit processors of Apple. When Apple released an announcement that starting February 1 2015 all applications to be submitted to the Store must include 64-bit support, we Unity developers were in little bit of confusion. While Unity has already provided the support for iOS 8, 64-bit architecture is still an issue.
But they have already been working to find a solution to the problem, and that is what we already know as IL2CPP. Well basically, it is just a runtime which combines an AOT compiler with a virtual machine to convert everything to C++ codes and thus it will deliver native efficiency and performance to the games we develop.
IL2CPP is still under heavy testing and it is hoped that it will be integrated with, much awaited Unity 5.