Vmware, Xen (and the article author) are all missing the point
We have now reached the point where it is necessary to provide proper networking features at the v-Net layer including merging correctly n x XG interfaces into m x virtual interfaces with trunking and other network protoocols working as needed on top of this.
Similarly we have reached the point where it is necessary to have the more advanced OS features like QoS, policing, reservations, etc all working too.
Neither of these are on the v-world horizon. In fact if you look at where they are going it is the completely opposite direction - transparent dumb VLAN passing to VMs using PCI virtualisation and killing all OS advanced networking features to achieve the required performance.
That already flattens out the network prior to any accel (as observed in the article). It cannot be the way forward. It is the way backward.