Since my first site just launched in April, I think I am still pretty well sandboxed. I only get 3 word search terms from google, and my PR is still 0. That said, the stuff I have read is google doesn’t link banner farms/aff link farms, and they don’t like tons of external links on a page. The way I am doing it takes care of both of those problems so I really don’t think it can do anything but improve your google results. Again, I am not a SEO masta so YMMV.
CBW