You mean season 3? I'm going to watch the final ep of season 3 soon.
GoT is one of the most pirated franchises in the history of the internet, so I don't know how much return on investment HBO or the production companies are getting. I've personally DL'd all the seasons, and purchased season 1 on Bluray. Season 2 is $70 on Amazon for some reason.I'm always worried about what they will do when they eventually catch up to the books, and how they will deal with the child actors rapidly out-growing their characters.
Nerver really been too worried about the productions costs tho, since i always thought the insane popularity of this show made it earn back the money it cost to make.
Also, I strongly doubt that the fans/actors would start "dictating the plot" and the studios would cave under the pressure and start making massive changes from the books.
Like the article mentioned, if someone like Tyrion or Danaerys or Jon Snow died in the books, the show might diverge drastically because they'd hate to lose stars like Dinklage or Clarke.