My experience thus far has been that I can make outgoing calls with no problem. Frankly, if I had to choose, I would have wished for the outgoing to be what stopped.
I found out by accident the other day, however, that the calls are still coming in, they simply don't ring.
I have my Google Voice number forwarded to my cell phone, but I also still have it forwarded to Google Chat (as used for the Obi110). A call with a client yesterday was dropped due to my cellphone's poor reception, so I picked up the phone connected to my Obi110 to call her back, and she was on the line.
To confirm, when she called again later in the day, when my cellphone rang I picked up the non-ringing phone connected to my Obi110 and answered her with no problem.