It'd be useful in the sense that you'd be able to warn others, but for your own password you should be using a password manager with auto generated random passwords. That way the only thing you need to do is change one password on the leaked site.
That's exactly my point. I use 1password to handle my logins, but most people I speak to use the same password for everything, so knowing how likely it is that other services could be compromised due to this is vital.
