Aha treasure trove! Don't know any of them!
I have been mainly following
Peter Diamandis (very techno optimist Bold and Abundance books, good antidote against doom and gloom media)
Gerd Leonhard
Tony Wagner (looks mostly at education, I find it interesting to see what he doesn't talk about, who is going to help existing professionals through this transition?)
Dan Pink (focusses more on the human side in the future, "A whole new mind" is what I based this article on
Hans Rosling (how not to be ignorant about the world, he shows that you need to watch trendlines not headlines)
James Altucher weirdly enough, he writes about alot but also is really into the concept of the idea economy. He has a more practical view on it, seeing from business how things have changed. Interesting perspective, he has been at rock bottom several times in his life and when you read his writing first he sounds like a screw up but I find him to be very reflective and provocative
I know of a few of those, Diamandis is obviously a pretty well known guy.
I've read quite a lot of Michio Kaku's and Kurzweil's work too.
Nick Bostrom is another one who is also very interesting.