Cisco VM-FEX Limitations

The week before VMworld on 8/25 was the Virtualization Security Podcast featuring Greg Ferro (@etherealmind), CCIE to discuss Cisco VM-FEX and its impact on virtualization and cloud security. VM-FEX is a method by which the fabric of a UCS top of rack switch is extended to the VM, but only if the VM is using VMDirectPath. So does this impact Virtualization and Cloud Security in any way?