There's a risk that Disney will screw this up, but personally it looks like something hard to get wrong. Disney has a huge library of unique, high-quality content people really want to watch. If they can put all of it — not artificially limiting the selection too much — on one service and set the price right, they should do well.
I thought that too, but the article makes a really interesting point, backed by Iger's quote, that they may not wrap Marvel and Star Wars in. Honestly, I have no desire to subscribe to their service without that IP and I doubt I'm alone. Of course, plenty of people still will, but will it be enough to make it profitable?
They bought their minority stake in BAMTech (the streaming spinoff of MLBAM) earlier this year. There’s no way they’re going to mess this up from a tech standpoint either.
HBO Go was totally redone from the ground up by the MLB team I believe and there were some hickups at the start but it has been pretty good since then.
HBO Go might be okay (I've never used it), but it's a rare day that I can watch a full episode of anything on HBO Now (Xbox One) without "We're unable to play this video right now. Please try again later". Netflix is the only streaming service which has performed flawlessly for me over and over again. You'd think it was a solved technology problem by now, but Amazon, Hulu and HBO Now still seem to have playback issues for me on a semi-regular occurrence.