I read this at 2:00 AM and wanted to re-read it before I posted a comment. I'm not completely sold on VMware NSX for network virtualization as it is yet to be even released. However, I'd like to hear some clarity around your statement that software based network virtualization doesn't support multiple hypervisors and doesn't scale.

As I understand it PayPal (48th most visited site on the Internet) uses Nicira v3.0 which tells me that it scales and they have over a combined 60,000 cores of ESXi and KVM running on their, I'm assuming virtualized network. I see this as a discrepancy between Cisco and the Software Defined industry (VMware/Nicira). As one of those bloggers that have been questioning the strength of VMware/Cisco relationship, I’d like to see specifics around these claims.