Is your virtual server secure?

I was reading an article over at Linux Journal which discusses security vulnerabilities within a virtual environment.  It appears that a recent study has found that virtual servers are being created but not being secured to the same extent as their physical counterparts. 

If you are using virtual servers, security is just as important if not more so then when using physical boxes.  While using virtual servers does make an administrators job easier, one has to remember that this new layer also needs to be as secure as possible.

Take a read through the article and if you are using virtual servers, think as to whether you have let security lax any.