Okay, let's turn down the rhetoric a couple of notches. There are two aspects to this -
1) This does not appear to be a case where the publisher just "changed their minds." 1984 and Animal Farm are, through the usual idiocy, under copyright in the US but not in other countries, so someone re-publishing the text without paying the copyright licensing is breaking the law, and Kindle customers have, in effect, been sold "stolen" property. (Equivalent: buying software that illegally includes GPL code). If you buy a stolen ipod, it can get confiscated by the police.
2) However, this does reveal a pretty worrying tendency to kill books first, clarify later. If Amazon had just sent out refunds, plus notes that "Due to an oversight, if you are in the U.S., this version of 1984 is unauthorized," that would have seemed sensible.
My suggestion - use the Kindle if you like (I love mine), but backup your books, strip the DRM, and pirate shamelessly. Casual piracy adds features to ebooks - the ability to lend and trade books, which is how we all got hooked in the first place.