Vitalik Buterin in interview for “Hidden Forces” suggested that we should use pay channels and Plasma if we as community can’t wait and if we want scalability now.
For complete dream and direct scalability in original blockchain(Sharding + Casper PoS) we will have to wait for at least few more years.
Scalability represents expanding of network capacity, increasing number of transactions per second on second layer similar as on Bitcoin Lightning Network.
When we mention second layer we refer to side chains, additional chains of transactions which areleaning on original blockchain and those are increasing permeability of whole network while original chain is intact and unchanged.
There are two Casper systems where first is temporary, cross over system, named Casper FFG and second system is named Casper CBC.
Plan from 2017. was to implement Casper FFG in 2018. which was supposed to work together with mining(PoW). At this point community would familiarize with PoS system and number of miners was supposed to decrease and their role in blockchain minimized.
Later, 2019-2020. Casper CBC was supposed to be implemented and that one is complete and true POS system.
Casper CBC will resolve issues with enormous electricity demands for ensuring security of network with mining that we use now. Further, CBC will decrease block time from 15 to 5 seconds and whole network permeability will be increased 3 times.
Sharding represents upgrade of original blockchain which is supposed to increase number of transactions for hundred times and it was supposed to be implemented last.
Early this week it is announced that Casper and Sharding will be implemented at the same time.
Obviously Vitalik made progress in Sharding research and testing on blockchain but still he is not ready to implement that technology at 2018.
— Vitalik Non-giver of Ether (@VitalikButerin) April 30, 2018
Vitalik implied that Casper FFG is not necessary hard fork while Casper CBC and Sharding must happen! PoS system was expected this year but from interview we can easily conclude that Vitalik and Vlad Zamfir are working and they are willing to implement Casper CBC and Sharding into one upgrade. Casper FFG(2018.) or Casper CBC and Sharding(2019-2020), it is a question and it is unclear which will be implemented at next upgrade.
On the other end, no one is mentioning so called “ice age” which is something that can’t be avoided.
At the end of 2018. Year blockchain is scheduled to slow down(freezes) if upgrade of protocol is not implemented. This suggests that hard fork must happen at the end of year, at least to postpone “ice age”. Purpose of “ice age” is to force Ethereum developers to do something until the end of 2018.(self-proclaimeddead line for upgrade)
Plan was to implement Casper FFG but since change in plans happened it is unclear what kind of upgrade will be implemented.
From all this we can conclude that PoW system and mining will be active for at least one more year. In July 2018. Bitmain will start to ship their ETH mining machines and we will see what will happen with number of miners and hashrate which are constant for months now.