On the Red Vs Blue site, buzby writes that the DVD of the first season of the Blood Gulch Chronicles is now at the duplication house, and explains what they did during the slight delay:

We sent the DVD out for testing -- which was mainly for our guys to make sure that all the buttons worked and that there were no major glitches. However, the universal opinion was that we needed more content. So we pulled the disc back in and added a bunch of extra features, including outtakes, easter eggs, additional footage and some extra stuff. We even made a new cover for the disc itself. Keep checking the site and we will be adding more info as we move forward.

After they finish making backups of last season, they'll start on the second.