I though that developing Ethereum ASIC would be unprofitable because of their plans to switch to PoS, but it seems like Bitmain has calculated otherwise. Maybe it will be usable to mine other coins with the same algorithm. But since it won't be able to mine all GPU algorithms, GPU mining will still be around for a long time, so if this ASIC will take over ETH mining, current ETH miners will just switch to other coins.