Canonical gave permission for Stack Overflow to use the Ubuntu trademark and logo for Ask Ubuntu. A Canonical employee also assisted in the site's new design to help meet the [Ubuntu Brand Guidlines][1].

Beyond that Canonical has made no public announcements relating to Ask Ubuntu. (So we must assume that the site is not officially endorsed by or related to Canonical).

(Note: There are Canonical employees that are members of the Ask Ubuntu community.)

  [1]: http://design.canonical.com/the-toolkit/ubuntu-brand-guidelines/