Looks like the first Ethereum asic ever released is coming to its end of life. According to a few people it no longer can mine ETC which is on Epoch 328.

Ethereum is about 11 epoch behind so it's about 55 days from being rendered useless. I wonder how many of the E3 miners are in existence and what effect it will have on the overall hashrate for ETH.

We will see what happens to the ETC hashrate after this however usually the ETC has a lot of volatility due to pool switching between ETH and ETC.