This is from the www.watchtower.org
http://www.watchtower.org/library/na/article_02.htm
When it came to God's name, instead of putting the proper vowel signs around it, in most cases they put other vowel signs to remind the reader that he should say 'Adho·nai'. From this came the spelling Iehouah, and, eventually, Jehovah became the accepted pronunciation of the divine name in English. This retains the essential elements of God's name from the Hebrew original.
and
Nevertheless, many prefer the pronunciation Jehovah. Why? Because it has a currency and familiarity that Yahweh does not have. Would it not, though, be better to use the form that might be closer to the original pronunciation? Not really, for that is not the custom with Bible names.
Now what would happen if a publisher would prefer the to use Yahweh always?