Not sure if this will help anyone else, but I stumbled on a way to get PAC-12 network without ditching my DirecTV contract.
I was calling Comcast to see if they had any promotions that could reduce my monthly internet bill. I was just billed $73 for October after my promotional period expired and was looking for a new promotion.
For $59 a month for 12 months I was offered the same 25Mbs internet with basic digital cable tacked on. I then asked if I would be able to add the Sports Entertainment package (includes P12 network) and was surprised that I could. It was added free for three months and will be $10 a month after that.
All I had to do was hook up a splitter by my cable modem and hooked up the box to my main TV. Unfortunately, the box isn't HD (and as old as I am, seriously... this thing is huge and ugly. See below.) and I can only watch it on one TV. I haven't been able to get the online access to work yet, but I was told that I should have access once I activated my cable box and is probably a timing thing.