The major change is going to be that we can't place outgoing calls using google voice. By putting a voip provider such as Anveo or Callcentric in the loop we can still get incoming calls to the Obi from our google voice number. Outgoing calls will also have to be placed through a voip provider, but those providers not have caller id spoofing so we can have our google voice number show for our outgoing caller id, even though the call doesn't actually go out through google.