AI is already our super intelligece
You say that no one knows when superintelligence will come. I've already said a couple times that superintlliigence is already here. Lest you think I'm a hack, one of these times was at the main international AI conference (IJCAI) at a panel chaired by Stuart Russell. All of our slides and a picture are here: oh, I think this site is blocking links, just google "ijcai 2013 panel future of ai", my blog post was second from the top when I did.
Nevertheless, I disagree with Ron Arkin. We do have a lot of big problems, like climate change, sustainability, ISIS and other radical changes to the political and economic order But all of these are symptomatic of the hypercomputation that our culture affords, that Bostrom predicts but can't recognise. Computation doesn't only take place in computers, and intelligence doesn't have to be on just one processor. Our entire society, machines and people both, are figuring out ways for humans and human organisations (including corporations) to succeed and compete, and in so doing accidentally causing a considerable level of mayhem, though also doing many wonderful positive things.
Overall I like your article for its balance. But I'd like more people to realise that AI is already here, and it's helping us change the world very, very quickly.