Since everybody on social media is ranting about Facebook's new coin here's my two cents…
Yes, it is a stable coin backed by a basket of assets. Think of it as a multi collateral Tether coin. It will use its own blockchain called Libra. The strangest part is that they call it a blockchain and yet write in the whitepaper that it isn't one. Probably they use the term "blockchain" only for marketing reasons. It will be scalable because it will be centralized with a few nodes securing the network. It will introduce smart contracts similarly to Ethereum and it will also introduce a new smart contract language called "Move". The new language should help developers make less critical mistakes. The virtual machine will be also more restrictive, meaning developers will have much less freedom when designing new assets.
My FAQ:
Will it destroy Bitcoin? - Definitely not, most probably it will have a net positive effect on BTC.
Will it destroy Ethereum? - Definitely not, both platforms are going in entirely different directions.
Is Libra centralized? - Yes! It makes EOS look completely decentralized.
What is Calibra? As far I understood it would be the wallet for the new coin.
Are they going to be able to censor transactions on Libra? Yes.
In a nutshell: Libra is not censorship-resistant, permissioned DLT, which will start as a fairly centralized system. It will have its use case if regulators allow for it. Probably it will be used by many people around the world. I am just not sure if people trust Facebook anymore.