And the conclusion is that, well, there doesn't seem to be any conclusion. Some names are borrowed in their entirety from English (e.g. Luna Lovegood) and hence lose their meaning (for those readers that don't know some English, anyway), others are translated in more or less obvious ways, and still others have one or two letters changed for no reason that I can see (why "Abelforth" instead of "Aberforth", or "Pettigrow" instead of "Pettigrew"? Mere convenience of pronunciation for French speakers? That seems the most sensible explanation I can think of...). Bizarre. Malfoy becomes "Malefoy", which is a mere grammatical correction (adding the E because "foi", as the contemporary spelling is, is feminine).

The most hilarious thing about translating the names in any language, though, has to be the desperate attempts of all translators to try and make some remotely credible name out of the letters of "I am Lord Voldemort". The French translator found himself forced to come up with the absolutely priceless middle name "Elvis" ("Tom Elvis Jedusor" to be exact). The Dutch translator came up with a rather elegant solution, all things considered, managing to put a typically Rowling-esque meaning in Voldemort's original name, albeit a totally different one from "Riddle".