It is clear that catering for the Arabic user goes much further than user interface translation and that we cannot regard such users as homogeneous:
An interface in Arabic is not necessarily the most important factor in reaching Arab users. Rather cultural appropriateness is most important, as it’s not about getting the content translated; it’s about creating the material that would be culturally relevant. There are important regional idiosyncrasies that need to be taken into consideration.
In the case of Facebook alone, 15 to 20 percent of users in the Arab world converted to the Arabic interface while some countries such as Saudi Arabia saw adoption rates increase. And all with little campaigning and advertising; underlining the case for localization.
Excellent thoughts on a subject we don’t hear enough about!