Support fair business practices. DRM isn't.
"... if your Kindle 1 breaks or you purchase a Kindle 2 all your Newspaper and Magazine issues will be UNREADABLE on the replacement or new device ..."
Here is one more, seems like committing to electronic formats you're asking for trouble even when upgrading to another version of the same product:
"... I have a tremendous volume of Kindle content (public domain and Amazon). I discovered that I could not directly transfer from my computer backup for Kindle 1 to the new K2 ..."
Another one:
"... Although Amazon says it keeps you content on their server, I found many instances where I could not download my books to my computer because the item THAT I PAID FOR was not available for download to my new Kindle2..."
iRex let you use open formats, and the software is also opensource and in continuous development: http://www.irextechnologies.com/