Originally Posted by tomsem
/system/thumbnails contains cover images for most (if not all) of the books that I have on my Kindle Touch.
While there does not currently seem to be a way to view these on the KT itself, it does suggest that at some point, Home view will get an enhancement so that you can view the items with cover images displayed.
More evidence, if any were needed, that there are features in the pipeline that did not make it for the initial release.
I don't think that one can draw that conclusion. After all, all Kindles can display thumbnail cover images, so it's not unreasonable that they should be stored somewhere.