The unfortunate thing is that, as someone on the Amazon boards (
http://www.amazon.com/review/RV0R3AO...#RV0R3AODMRNJZ) has experienced, if you have a broken Kindle and get a new one you can still be screwed out of content you've bought if the publisher pulls the ebook rights from Amazon.
Even backing up to your computer does no good since the backup would be tied to the OLD broken Kindle. and forget getting a refund. At least according to the reviewer in the link above. THAT is a serious issue. You force people to deDRM your content to back it up or you risk losing what you paid for??? serious issue.