A client of mine had his website excluded from the google SERP. According to his version he has done nothing wrong. His SEO strategy was some AdWords, posting to forums (sometimes the same content) and exchanging links with similar sites).
Should I recommend to wait and see? Or is there something that he could try?
As long as you don't have duplicate content, titles, etc... I would wait. Changes are on the way with google. I have 3 sites that dropped but lately, every now an then I see them pop back in at a higher rank.