Ellinor Michel (ICZN Executive Secretary) is quouted in this BBC News article on species named after famous people. The article was inspired by the recent naming of a fish after British scientist Richard Dawkins and a crustacean parasite of fish after reggae artist Bob Marley.
"First of all you need to identify a new species, found either in the field or in a museum, and support that identification of its uniqueness using data on the morphology (physical features) or genetics. The species needs to be clearly, repeatedly different from other species that it might be related to.
You then publish the findings in a scientific journal, ideally one that is peer-reviewed. This means that other specialists subject your work to critical scrutiny, improving the scientific reliability all around.
At this point you can give it a name, that you feel reflects well on the discovery - naming it for a special feature, for the place it occurs, or in honour of someone you respect. If you publish it according to the rules, the name sticks for perpetuity."
Dr Ellinor Michel, International Commission on Zoological Nomenclature
Read the BBC News article: 10 species named after famous people