said by en102 :

Filtering / eavesdropping on my connection will keep me from signing any business (personal or other) with AT&T.

While I might have applauded AT&T for attempting to do FTTN as a viable product (jury is still out), playing buddy with NSA, on my calls is obviously not appreciated, and content filtering /deep packet inspection of my traffic is even worse.

said by Matt :

Given the fact that AT&T transfers the majority of the internet backbone traffic, you may not have a choice, no matter WHO your ISP is.

said by jester121 :

But most of the companies that actually ARE wholesale customers of AT&T WOULD welcome this -- less bandwidth to purchase from AT&T (thanks to thwarting pirate bandwidth hogs) = a few more months in business.

Why do you think they would defect en masse?

said by odog :

Because your customers would defect from you. If I was a customer of an ISP, and my ISP only used AT&T for their internet connection my customers would get mad at me for not being able to use P2P. Also if you are a business level customer you buy raw, naked internet, with no restrictions.

said by jester121 :

Plenty of small businesses wouldn't mind AT&T filtering potentially illegal traffic from their network; it saves them some expense in installing filter/block software.

It all comes down to which direction the market takes. I'd say the vast majority of customers are going to shop price and speed, and if they find out afterwards that P2P doesn't work, they'll get over it.