Good start, one of the aspects of this I would like to see addressed is the fundamental difference between Android and iOS when it comes to implementing a Type 1 Hypervisor, which is really the only rigorous way to enforce any security.
This is a good article. I find it interesting. Is short and only touches the basics but it really feels as an introduction towards what may become a great follow-through series of articles.
It was interesting to learn the different terminology used for Android and iPhone. Like Jailbrake for iPhone and Rooting for iPhone. etc.