Very interesting analysis of why the launch issue is 500Mb:

I mounted my jail broken iPad via AppleTalk and quickly tore into the app itself to see how it was constructed.  Similar to the PopSci+ magazine application, each Wired issue is actually a bunch of XML files that lay out a bunch of images.  And by “a bunch of images” I mean 4,109 images weighing in at 397MB.

Each full page is a giant image - there are actually two images for each page: one for landscape and one for portrait mode. 

No text, but instead two images for each page? Yikes.