Linux and maemo5 now uses a telepathy observer component to listen for incoming calls. When there is an incoming call from the GV number, it will understand that this call is because of our dialing through GV. The intended result was to auto-accept the call. For the moment, it will just automatically dismiss the dialog box that allows the user to cancel the call.
I was pleasantly surprised to find that the telepathy observer is able to listen for an incoming phone call on SIP, Skype as well as GSM phone on the N900. On Linux if I use empathy and nokia-sofia-sip, then it is able to hear an incoming sip call.