We check this website, now i2c-bus.org is up and dont blocked for our system and other users of the Internet.
So, answer to question: Is i2c-bus Down Right Now? - NO! i2c-bus is up!
If you have problem with access to site i2c-bus, and domain i2c-bus.org is not avalible.
Clear browser cache and/or try other web browser
(Chrome, Firefox or Safari).