The links in the README file are currently dead

[jd-boyd]

Checked as of Feb 3rd, 2013, I get 404 pages.

[DrPizza]

I'm hoping it'll be a temporary issue; I had to disable tumblr's custom domain temporarily (I was using an export tool that doesn't like custom domains), and for whatever reason, it doesn't turn back on instantaneously.

In the meantime you should be able to the posts at:
http://flaming-grackles.tumblr.com/post/4906301357/grand-central-dispatch-for-win32-why-i-want-it
http://flaming-grackles.tumblr.com/post/4916668260/grand-central-dispatch-for-win32-the-port
http://flaming-grackles.tumblr.com/post/4919777397/grand-central-dispatch-for-win32-the-source-code
http://flaming-grackles.tumblr.com/post/4929297740/grand-central-dispatch-for-win32-things-still-to-do