Obviously it's not going to keep up forever. For the next half a year or so though? That certainly seems possible at least. There's an insane amount of network power that's already been pre-ordered and just needs to go into production already.
Of course, but once you recognize whats creating the growth you realize that it's not actually an exponential process— it's not like more hashpower begats more hashpower like breeding rabbits. Hashpower comes on line in fits and starts as chips come off assembly lines. In the long term I like to think about mining as a process that decays words low profitability for the most power efficient miners... but right now supply is manufacturing side limited, not competition limited (relative to power costs mining is insanely profitable still)... you can pick any result you want just by picking parameters and just about any result is equally (in)sane.
Trying to predict price from difficulty has failed for everyone historically— no shocker because it makes no sense to do so. Difficulty has closed loop control from the system, it'll be whatever it needs to be to control the blockrate. When difficulty makes mining not profitable enough people stop mining and the difficulty drops. More than half the coin that will ever exist is already in circulation, miners are in little position to dictate market prices to improve their profitability, but in a lot of position to turn on and off.
