It has long been known that one of the main objectives for Vitalik Buterin, the creator of ethereum, is to lead this blockchain to use a POS protocol; however, it is always advisable to state this, it is Vitalik himself who believes that before he can implement such a protocol, which replaces the POW currently used by this blockchain, it will take years. While waiting for this fateful day to arrive we are however approaching the 9.069.000 block (which will presumably trigger the Istanbul fork on December 7th) and to what will be the last hard fork planned for Ethereum 1.0, the one that will finally open the way to Serenity which, in turn, is the first step to get to the 2.0 version of the platform; before this happens, however, it will be necessary to wait for the update of the EVM as well as the implementation of Casper, that is the new POS protocol without which ethereum 2.0 could never come to light. The feeling is that in the end the developers will move towards an intermediate step, during which both the POS system and the POW system will be active, in a sort of hybrid blockchain that could end up looking somewhat like decred; at that point who knows, the transition to a 100% POS system could continue or eventually the developers could opt to keep the hybrid version of the blockchain (which is still a possibility).

For now the developers have only agreed on one thing and that is to postpone what was called a "trouble bomb", which will therefore not be launched with the next hard fork but which has been moved farther away (as much as 4mln more blocks) come on); however, we clarify for the most distracted of what we are talking about, the difficulty bomb, as the term itself suggests, is nothing but a mechanism that would increase the mining difficulty, introduced to stimulate the transition from the POW protocol (which due to of the difficulty bomb would require enormous computing power and, therefore, high electricity consumption) to the POS one. Since, as mentioned, the transition to the proof of stake protocol is still very far away, the choice of the developers to move the expected date for the 4mln block bomb (that is, in about 700 days) also gives us a detail on how much the phase in which the ethereum blockchain will remain hybrid may be long; the launch of Casper, in fact, is scheduled for next spring, so it is likely to think that for at least a year and a half both protocols will be active on ethereum, until in just over a couple of years, the explosion of trouble bomb will stimulate the migration of miners from the old POW protocol (which has become too expensive) to the new Casper. So to finally see the 2.0 ethereum it seems we will have to wait for 2022, until then we can only prepare ourselves for Istanbul.