The VMware architect designing the ESXi 5 rollout wants to use Nexus 1000v but only for the 10Gb ports that will carry application data. For managment of the ESXi servers and vMotion etc plus mangment and control vlans for the VEMs he wants to use 1Gb ports running a standard VMware switch. This will be a L3 deplyment of a 1010 by the way.Will this work or does the L3 connection to the VEM have to go via the VEM itself ?
If you are going to run L3 than the the you have to put the L3 vmknic under VEM control. Unfortunately there is no way around that. The issue is the VEM doesn't know which interface to send control traffic out of until you add a vmknic to the VEM with a port-profile set with "L3 Control".
All the other management interfaces can be on the vSwitch. No issue with mixing vSwitch, VMware DVS and N1KV on the same ESX/ESXi hosts.