I just thought I would put it up here as I know some people like to follow projects that they may find interesting. I've created a new project on codeplex that will eventually enable people to natively pull meta data information from M4A files. There is currently no freely available or open source tagger of this kind that works with .net so it should be interesting.

Do note that most information on M4A is from research, old data and a hex editor so the project may be slow to mature. I tend to work on this at least 2 times per week.

http://metataggercore.codeplex.com/