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