On Today's Ethereum Dev Call It was decided to delay the POS (Proof of Stake) update aka Casper, and also roll back the difficulty bomb as it will impact blocktimes significantly and it was meant to be timed to coincide with. The rollback will be called the Metropolis Byzantium update. However, this roll back won't happen for a few more weeks so 2 more difficulty bombs will likely still go off before it can be applied.
CryptoMines wrote a much more detailed summary on Reddit. Jump on over and take a look at his notes regarding the Dev Call Earlier this evening.
https://www.reddit.com/r/EtherMining/comments/6t56a0/important_information_from_todays_ethereum_dev/
