Trend Micro predicts that the proliferation of Android devices, smartphones and tablets is making all systems based on Android an attractive target for hackers.

http://www.mobilitytechzone.com/topics/4g-wirelessevolution/articles/244561-hackers-eyeing-android-devices-scada-systems-2012-prediction.htm

The NSA has released a Secure Android Version:

http://www.informationweek.com/news/government/security/232400479

Security Enhanced Android can be found here:  http://selinuxproject.org/page/SEAndroid

Then there is Project Fishbowl, Secure Android on a Secure Network:

http://www.theverge.com/2012/3/2/2838729/nsa-project-fishbowl-secure-android-devices-network