On every job from Careers, the "Joel test" string is translated to "Test de Joël" (note the diaeresis sign (2 dots) over the e) in the French version. The diaeresis (also called trema) is used to indicate that the e must be pronounced.
It's surprising because I don't think it's common to translate names in French. For example Peter Jackson is not translated to Pierre Jackson (even if Peter and Pierre are translations). There is an exception with people whose names are now known in History, for example Alexander the Great is Alexandre le Grand in French (this example is not the best because his real name is in Greek but you get the idea).
So I think it should be changed to "Test de Joel" because it comes from "Joel Spolsky", not "Joël Spolsky".
See this random example and switch the language at the bottom of the page in order to view this.
I just saw that it may be a choice from Joel himself, see his own website:
It's the same on Wikipedia: