Just a few hours after reading about it on Gizmodo, I got an e-mail from Comixology that one of my purchases was available for the DRM-free backup program, so I tried it out. Gotta say it's nice that they let you know when issues become available so you don't have to just keep checking back.
From there, I went to the site, and checked the backup tab to see which comics were now available. Turns out it was just one, but it's a start.
You are able to choose from two formats, PDF & CBZ. Once you select one, you get a pop up noting that this is for your own personal use only, not for distribution, and that each backup is watermarked specifically to you. I'd provide a picture, but I already clicked the "ok" box after checking the "don't show this again" box. Watermarking is also how digital copies of movies get tracked if one leaks out, and if it's still DRM free I'm fine with that.
Here's what the PDF version looked like, using Adobe reader.
Provided more of these become download eligible, I'd be able to store them on a flash drive and read them on a plane without using up data for streaming or what little storage space is available on my 8GB Nexus 7.