Attempted to update via drush and got
"File advagg-7.x-2.x-dev.tar.gz is corrupt (wrong md5 checksum). "
I just downloaded the file and got the correct md5 listedhttp://drupal.org/node/1887370
In the future if this happens again, download it again. An issue like this is 100% out of my control.
Drupal is a registered trademark of Dries Buytaert.