Android Device Manager is out
Google announced the Android device manager a few weeks ago and it has finally been released.
Remotely wipe (Factory Reset) your device
Ring your device loudly for 5 minutes, even if it is on silent.
The only thing you have to do on each device is allow the Android Device Manger to be a device administrator (which uses the same functionality as work/exchange email clients for remote resetting). On stock Android devices (e.g. Nexus) you can do this from Settings > Security > Device administrators > tick 'Android Device Manager'.
This has been a long time coming and I see this as step one of the fully cloud device management solution I'd always pictured (e.g. everything iTunes can do without installing any software on a PC). Also a much more nicer, google friendly integrated solution that the the ones that Android OEMs have been supplying.
You can access the Android Device Manager here: https://www.google.com/android/devicemanager