There will be no ASIC for Ethereum because it is a memory-intensive algorithm rather than a CPU intensive one (GPUs are just many CPUs plugged together). So there will never be one for it.
I do not think so, many advanced mining rigs has already done, using GPU and memory as in video cards. I googled "ethereum asics" and found devices like this one
https://www.nvminer.com , they call it an asic, but it still use NVidia GPUs. however, the hashrate and power consumption are more profitable, than graphic cards.