Without finding the MAC address, I got it to work last nite using my galaxy nexus ph.
I don't know why, but when i went to use my PC I could not connect to the interest. Turns out my ph was still connected to the chromecast. So when on the ph I turned off its wi-fi I then on my PC was able to get internet access.
That seems odd to me.
Hoping for Google to send out an update soon.