Mining was mainly done by ASIC because GPUs miners rather chose other coins. Now they are flocking back to Monero. And hash rate will soon go back to close where it was. Those 850MH/s will just do what they do what they want. They are getting replaced as we speak.
GPU miners abandoned Cryptonight due to the massive difficulty spike - initially thought to be botnets, and now we think it's the ASIC'S.
Price of Monero influences miners, higher price, more miners leading to higher difficulty and reducing mining profitability.
Mining hash eventually gets redistributed to balance out profitability amongst all coins.
Once the dust settles from all the forks I expect Monero price should improve - I don't think we'll see 500 though in the short term - hopefully it recovers above 200