At this point, the elimination of books with homosexual content (some of them completely unexplicit) from the amazon search and sales rankings doesn't look to me any more like some half-assed effort to bend to pressure. It looks like serious, intentional policy, though I hope it isn't from the top.
I expect things to get even more interesting when whoever had the bright idea gets identified.
Link thanks to jonquil.
copperbadge has the most thorough discussion I've seen with definitions and where to protest and updates.
Addendum:Here's an interesting theory that it really is enemy action by people manipulating amazon tags for books. On the other hand, there are previous statements from amazon that they had a new policy for "adult" material.