One thought I've had recently was that it would be very nice to have, for each ebook, a single download that contains all the formats that have been done. E.G. most uploaders upload at least PRN, IMP, and LRF versions of each ebook. It would be handy to have a RAR version that contains all three (or more) variants.
This occurred to me when I was contemplating the purchase of a new ebook reader which uses ePUB versus the PRN/MOBI that my current ebook reader uses. I have well over 500 ebooks at this point and re-downloading all of them would be a very time consuming process. In examining my elibrary I found that those ebooks that I had gotten from Baen books CDs had many many formats (doc, htm, lit, mobi/prn, prc, lit, rb, and rtf) while the ebooks I had purchased directly from Baen were only in mobi/prn and/or htm. (At this point I remembered having to graduate from html to mobi/prn when I got my Kindle when I only had 200 ebooks or so). When I added in those ebooks I had gotten from here, PG, and other sources around the internet the process looked overwhelming.
I am instituting a new policy of downloading every format available for each ebook I acquire to insure flexibility but it would sure be helpful if they were prepackaged, so to speak.