The CDC has an excellent page called evidence that HIV causes AIDS. http://www.niaid.nih.gov/factsheets/evidhiv.htm
It is not a fact, since nothing in science is. But it is a good theory and it is more than correlational. There is also a causal element. Having one seems to cause the other. Plus, what we know as AIDS existed before the advent of antiretrovirals.
Please, before you discount the theory altogether, go look at the page.
Thanks for the link. I had a discussion with John Valentine last week. I guess to no avail.