Stephen Bainbridge has an excellent post on the need for academics to disclose conflicts of interest–specifically, who's funding their research. I agree with Steve 100%. If someone's paying an academic for research or for consulting related to the research, I want to know about it.
A conflict of interest does not mean the research is unreliable. (I'm sick of both the left and the right dismissing research out of hand because it was funded by the right-wing [Fill-in-the-blank] Foundation or the left wing [Fill-in-the-blank] Institute.) But, if someone's paying an author for the work, I am going to pay much closer attention to the methodology and the analysis, even if the author otherwise has a good reputation.