I'm researching Ethereum mining, and I read Vitalik's interesting essay on how to design a mining algorithm
. In the last paragraph, he said that as long as ASIC speedup is less than (H+E) / E, then it won't be economically feasible to buy ASICs. Has that proven out? Has the dream come true, that Ethereum is just mined by hobbyists with spare cycles on their purchased-for-other-purposes GPUs? Or are we / will we see the rise of specialized mining farms?