> "Blue pill" attacks on Vista and Xen [...] Her work demonstrated that hardware virtualization is not in fact the security panacea we wish it was, but that it too is vulnerable to attack just like any other layer of the stack.

Blue-pilling is a method for malware to hide from the OS by virtualizing it, not an attack on VMs. That's why it's called "blue pilling". I do agree though that VMs are not airtight and VM escapes have been demonstrated.