Good joke. You guys realize that Bitmain sells GPU rigs? They wouldn't have started selling GPU rigs if they had an ETH asic in the pipeline and release it 6 months later
(1) Bitmain has already done similar things in the past. They released the S7 in Oct 2015, and barely 8 months later (Jun 2016) they released the S9 with next-gen chips & better efficiency.
(2) Bitmain's GPU rigs, even if obsoleted by an Ethereum ASIC, will still be viable for any of the numerous other GPU mineable coins.