IMHO, the best course of action would be to have an
open-source ebook reader for iOS. Mind you, this *could* be charged for (cf. Wesnoth being F/OSS and still being sold on the AppStore) anway. (And here I'm looking at you, iOS ebook reader devs. :-) )
Let's face it, there's (almost)* no other way to stop any determined company (like Amazon) from buying and subsequently burying a closed-source software (like Stanza, Bluefire Reader or MegaReader, just to name a few).
Because in the end, when it comes to non-trivial amounts of money, most of us (including myself) will give in or will be forced to give in to secure the survival of a company.
(* "almost" because there's the KDE Free Qt Foundation (
http://www.kde.org/community/whatisk...foundation.php) but that's not something viable for a smaller project like an ebook reader)