I might just be a little dumb, but is there an official announcement, and/or countdown until Ethereum cannot be mined? I can't seem to find anything definitive.
no notification for this yet. even from the latest information i know, it looks like ethereum 2.0 is not a new network rather it is like layer2. so their development is like starting all over again. unlike the original plan of those who wanted to create a new network, maybe they were in trouble. so maybe the announcement about the launch countdown won't be made any time soon.
They are no difference, some people would say that the ETH 2.0 is another token, but that is not true, there is no ETH 2.0 token. And it is now referred to as the consensus as the other comments have pointed out. The development is a step by step progress, and it has about three stages: the Beacon chain, the merge, and the Shard chains.
The Beacon chain has already gone live in 2020, so it is the Merge that would be next, and it should be anytime this 2022 according to information on their website and other media websites. The final stage which is the Shard chains would somewhere in 2023. Whatever changes that were made are for the better.