VMWare has virtualization working on Android, which supports this in a heavy-weight kind of way. See http://www.engadget.com/2011/02/15/vmware-android-handset-vi... and http://arstechnica.com/business/news/2011/09/samsung-boosts-...

The use-case for it usually suggested is one VM for work, one for personal use, but it could be used for this scenario too.