If the destination port group on Distributed Switch has the correct configuration, the network interruption will be minimal, maybe 1-2 pings, depends on how fast your physical switch updates the MAC address on CAM.
You can use the migrate virtual machine network feature on distributed switch or just go to the VM settings and change the port group where VM is attached. See the following link with the migrate virtual machine network feature: VMware - How to Migrate VM's from DVswitch to vSwitch ? - UnixArena
