Mining just isn't worth the trouble anymore. Unless we see a huge surge in price or the prices of miners slashed, its just not profitable to the majority.
I have a feeling we will see sub 300 prices within the next 2-3 weeks.
The big players can mine close to the line between cost of mining and value of mined BTC. Any huge surge in price will be followed shortly afterward by a huge surge in hashrate and the onflow of rise in difficulty.