No. Why does everyone have so much trouble with this concept? Reading this thread would lead me to believe that no two people on FR would agree on what the hell religion is!
Try this:
Theist - believes in a deity or supreme being as the basis of a worldview.
A-theist - has a LACK of a belief in a deity. This is NOT the same as a DISBELIEF. He just doesn't have the belief. This is what a lot of folks wrongly call agnostics.
Anti-theist - One who BELIEVES there is no deity. This is what most of you are (incorrectly) calling an atheist. He believes (is sure) there is no deity. Where he gets this belief, I don't know. It seems to require some faith, as he can't PROVE there is no deity, as you cannot prove a negative.
So, I wish folks would get their terminolgy consistent if they want to be able to discuss such things.
My take on it - anti-theism requires faith, not proof, and thus MAYBE could be classified as a BELIEF system. But real A-theists, having no belief, cannot. Remember the main point - the lack of a belief, and dis-belief, are two entirely different things.