I'm not sure whether it was the HN posting, but it seems Tumblr is not coping with the amount of traffic. Whilst that isn't all that interesting, I just wanted to say kudos for having a link to charity on the error page:

  We're very sorry
  Our servers are over capacity and certain pages may be temporarily unavailable. 
  We're working quickly to resolve the issue.

  In the meantime, please consider donating to the Red Cross 
  to help those in Japan who are in need of support.

Unfortunately, the link provided is broken:

http://www.ifrc.org/en/get-involved/donate/donation-japan

Anyone from Tumblr watching?