Ethereum Metropolis proposes to delay difficulty bomb for 1.5 years
There is a new EIP that was submitted to Ethereum GitHub repository about a week ago as a result of collaboration between Vitalik Buterin and Afri Schoedon. If it goes through, we can see difficulty bomb delayed for approximately one and a half years meaning that time to mine one block will remain around 15 seconds till late 2018 and will increase to about 30s closer to its end due to difficulty bomb kicking in.
In comparison we are currently fluctuating between 19.0–19.5 second block times and this is set to increase quite a bit by the end of the summer due to currently active difficulty bomb aimed to result in ice age. Good news is that Metropolis should be pushed around same time when these block times become too high.
In general this is good news if you are invested into mining or are developing decentralised apps based on Ethereum, however we must remember that there is a high chance that current mining reward will be decreased from 5 blocks to 3 in order to account for inflation, so do take this into account as well.