Microsoft has come with Microsoft Security Essential, this was the long waited initiative from the Windows users. Also if the OS Developer works for working against threats that will be the best way for it. Google and Apple as well can focus their development and will be able to provide best possible security solution.
Security was a factor in my decision to go with Apple rather than Android for my tablet and smartphone. I can't say that I have 100% trust and confidence in Apple's policing of apps, but on the other hand, the Android Marketplace is a wide open free-for-all.
Apple is policing the apps that are submitted to apps store. I am sure they at least check the data traffic going between iPhone/ iPad and network. The policing process has increased the time to market of the apps. Nonetheless, it helps protecting the apps users.
What policy has Google added? Is policing enough to keep malware and threat away? Is there other better criteria to keep yourself from "trouble"?