I'm not looking forward to that day at all, honestly. I want to experience the ending of this story through the books and while I certainly wouldn't watch any past-the-material-in-the-books seasons, it's going to be hard going to the Internet without people spoiling things left, right and center and then wondering, "But WILL this be what actually happens to Tyrion?!" or whatever.
I understand the practical reasons for this, but so far, I've been able enjoy the show as an enjoyable, simplified version of ASoIaF with some nice actors and pretty visuals, but when it gets to the point where it actually affects ASoIaF proper and starts disseminating information and plotlines for things I don't want to know about yet... I'm just, well, not looking forward to that day at all.