http://arstechnica.com/security/2012/11/crypto-keys-stolen-from-virtual-mach...
Some of our members have been convinced this was imminent for, oh, about a decade now. It's finally happened, but as is pointed out, relies on side-chanel attacks on shared hardware. This STILL doesn't mean virtualization itself is inherently insecure... but it does mean public clouds just got a little harder to trust for high-security operations. -Adam