Atheism as the null hypothesis.

[Jehanne]

Atheism is not the default position. It is the agnostic's position that should be the default position.

1. There is no God.

This is either true or false. Atheist believe this to be true. Agnostics don't know. Theist believe it to be false. Verificationists think the statement meaningless. Even if evidence and argumentation fail at proving there is a God, that does not mean there is no God. To say there is no God is a claim to knowledge and must be justified.

If you are defining atheism as an absence of belief in God (as I believe many of you like to do), that would only be a psychologically state. In that case, "absence of a belief in God" cannot be the default position because that would include a wide range of views: traditional atheists, agnostics, and verificationists and therefore incoherent.

Agnosticism is, of course, a statement about knowledge; atheism is a statement about belief, or, rather, the lack, positive or negative, of a particular belief.  A true agnostic would regard the existence of god, any god, to be a 50/50 proposition.  Dawkins' scale comes to mind, which certainly, IMHO, deserves a promotional place on a Starbuck's cup.