I thought I would post this here to save people some headaches...
My pop-in-law called me last night (after having called Shaw and booking a service call) to tell me that his Internet had stopped working. Shortly after, my son also called about the same issue.
Being that he had McAfee AV installed from Shaw, I knew that there had been some issues with lost internet connectivity regarding a recent DAT update (from Aug 17). I had him go through their recommended repair steps and this resolved the issue. I was a little surprised that Shaw booked a service call when they could have done this over the phone with him and started to think that there would be many others who would likely run into this issue.
The resolution to this situation is pretty simple and McAfee has provided the steps.
Simply go to http://service.mcafee.com/FAQDocument.aspx?lc=1033&id=TS101446 and follow the instructions. They will have you download a small tool (likely in safe mode) that will fix the issue and you'll be back up and running in no time. You can also follow their blog posts on Facebook via facebook.com/McAfee.