In the current freethinker discourse, agnosticism and atheism are considered to be independent properties - "gnostic" meaning "believing knowledge is possible" and "agnostic" meaning "believing knowledge is impossible". There was a very active agnostic theist poster on the forum then known as the Internet Infidels Discussion Board when I was a regular, for example.
Even if this were not true, changing the definition of the word "atheism" merely means that the word no longer describes the people you are disagreeing with - not that their opinions must correspond to the new word.
(If you are a YouTube fan, QualiaSoup's "Lack of belief in gods" is a pretty good overview.)
This is our monthly thread for collecting these little gems and pearls of wisdom, rationality-related quotes you've seen recently, or had stored in your quotesfile for ages, and which might be handy to link to in one of our discussions.