We have it as a task. The biggest issue we have with doing it, that we'll have to investigate, is that Joomla loads the language strings of the currently logged in user. On many single-language sites, this isn't an issue. However, if you have a site where the user can select from multiple languages, whatever language the user has selected will dictate the language of the email sent to the administrator.
Hopefully, that should be easy to overcome to force the Joomla default language.. shouldn't be too tough
We'll keep you posted on this, and definitely agree that more language translations are better.. we strive to get them all in there, and are pretty good, but sometimes we get lazy, and apologize for the inconvenience.