PZ Myers wrote an excellent article on him. Here some of it is.
Curiosity is a fine thing and I have to encourage any wellspring for it. However, the defining feature of Collins' faith, and that part of it that makes it objectionable, is that he uses it to wall off parts of the human world from curiosity. The human genome project was a technological exercise, a sustained, disciplined effort to apply developing tools to a specific, narrow problem. It opens up new avenues for science, but in itself was not a demonstration of scientific competence. His administrative ability led the work to a conclusion, not his scientific skill set.
And what has he done with it afterwards? Declared the genome a divine artifact, decreed that certain domains, such as human behavior and morality, are exempt from scientific scrutiny, and proposed a succession of freakish Christian dogmas as substitutes for reasoned analysis. At this point, where the real science takes over, his faith only gets in the way.
And please, don't ever equate faith with ethics. They have nothing to do with each other, except, perhaps, that faith is a commonly used escape clause to get away from the requirements of human morality. Science itself is a tool, as amoral as a hammer, and it certainly can be misused, but don't go crawling to the priests for guidance. Let's hear from philosophers, psychologists, sociologists, and lawyers long, long before we consult with theologians—I can't imagine a worse fate for scientific ethics than for it to fall under the sway of a dogmatic Christian.
I would rather Obama had appointed someone who wore practical shoes, and didn't make much of a fuss about them, anyway. And excuse me, but I don't want American science to be represented by a clown.