Another interesting post on how Virtualization impacts DR/HA. 

http://www.eweek.com/c/a/Data-Storage/Survey-of-IT-Execs-Virtualization-No-Panacea-for-Data-Recovery-832514/

I think a lot of people just assume that once you virtualize systems, that the result is easier DR/HA.  As with any technology, it’s just part of a large solution and needs to be understood before deployment.  Even more importantly, is understanding how Virtualization can impact, update, and even enhance your existing DR plans.