Wanganui
Strictly speaking, Whanganui is the correct spelling, no one is doubting that. However, for a place name, does the correct spelling really matter? I can name at least several places with incorrect names in other languages. For example, Britain in Chinese "英国", is only a transliteration of the word England, conversely, the name Macau does not reflect the area as whole as well. German people should be deeply offended - if my memory serves me right, Japanese and Chinese are the only two languages which have correctly transliterated Germany's real name, Deutschland.
Of course the name of Wanganui is originated from a Maori word, however, since it has entered general usage in English, it should not be treated as a term for an exclusive group.
The name of Wanganui has its value too. It is the reflection of the history of interactions between Europeans and Maori, and the evolution of local iwis. I remember my teacher once said that the pronunciation came from a tribe from South Island, but it's no longer there anymore. This is history too, and the name of Wanganui reflects this fact.
Name change requires a lot of money too, and this country has too many important things to spend money on rather than this. I think a good solution is to make Whanganui a offical Maori name but continue to use Wanganui in general usage. If people starting to like the way it is spelt with h, then change the name. At end of the day, language is the movement of people, not bureaucracies.
