Talked to Directv for a while today. They said non-subscribers will be allowed to subscribe to the online only (incl iDevices) Sunday Ticket for $250. This should be available on September 1 on the page http://www.directv.com/sundayticketspecial.
I'll believe it when I see it but this could be a very nice option. I'll report back when I see the option live.
I *tried to order it as a non-subscriber. Bottom line - you can't. I'm in Florida and would love to have had online access to some of my favorite teams. I even went up the ladder when I called and spoke to *multiple supervisors. Spoke to at least 6 people. None of them will sell you online Sunday Ticket access if you don't physically have a Direct TV dish with an active subscription or a PS3. Also that link you posted just goes to the main Sunday Ticket subscribe page, no online only ticket special exists and the season has started so it's not gonna happen.
Sad that someone like me willing to pay has no legitimate option here. I guess I'll jump in and watch via the non-legitimate options.