There seems a sign that central bank are currently interested in the blockchain. So what will be the effect on current cryptocurrency if central bank release their own coins? will it be a good news?
A lot of banking/financial institutions are interested in blockchain. This shouldn't necessarily mean that they intend to launch their own form of crytpocurrencies. Even if they do, most people won't use it. At least most who understand the concept of crytpo. Can we expect to see a central bank starting an open source project in a Github repository anytime soon??
Banks maybe interested in other capabilities of blockchains like implementing smart-contracts. That too may only be implemented in the form of some products with customers. For example, giving you a bond over their blockchain that you can verify and see on a blockexplorer. Something of a novelty to their old, crazy-rich elites. But there is no chance in hell that they are going to start transacting over a transparent blockchain for everyone to see the movement of funds.
Making that movement transparent amongst the biggest banks is what bitcoin is meant to do in a plausible future.