The athrophic principle is not a ontological or developmental theory, it's simply a answer to the Contingency of the Universe question, or the fine tuning question, the question is not whether or not it is true, it most definately is, it is whether or not it is a sufficient explanation or just tutology.
Here is an example:
Questioner: Why do we observe a universe that seams fine tuned to develop conscious life.
Theist response: God designed it as such.
Atheist response: The anthropic principle, any universe that IS observed must necessarily be one who's laws of nature lead to conscious life, a universe that didn't have such properties wouldn't have anyone to observe it and thus no one to ask the question of why. Thus the question is trivial.
It's used often as a response to theists (of which I am one), and i find it interesting that I (a theist) is arguing the anthropic principle against paralogic (an atheist).
I don't buy it as an explanation, but its patently IDIOTIC to claim, as paralogic did, that it has been "proven" wrong, he throws that word "proven" around so much it's become meaningless.