i believe there is a lot of great features being added as the newer versions roll out but I feel like they are becoming more vulnerable at the same time. I have been up all night playing around with kali linux attacking my ios 7 phone and I am pretty confident that with in the next year it will be terrifying to even go to a Starbucks with out the right protection. It is scary how easy it is for someone to dump your address book or pictures in to a database in less then ten minutes.
Although that was the reason I was up all night playing with it. I think there is a great opportunity to start development on antivirus and support for malicious attacks.