Matt Alexander nails it with his sentiment on the significance of this:
On-demand digital programming is the future. And original programming will have to exist within that environment. Simply put, the only company truly succeeding and acting aggressively upon this reality is Netflix. And I cannot help but think it'll benefit them in the long-run.
Nevertheless, HBO will invariably be watching Netflix's performance with a keen eye today. If that were to force their hand, I'd be the last person to complain.
I don't get HBO as part of my cable package, but I wholeheartedly agree with Matt here. On-demand digital programming is the future, and I can't wait until it arrives. I'm a big fan of TCM, and one of my dreams is to have their entire film catalog available on-demand. So, if I want to watch Claudette Colbert bathe in a vat of milk at 2 in the morning, then I can.