spiros:
Too many people have differing views on how such a standard should be built, which is why we have so many different file types. In many cases new file types are justified. In others they're simply different with no real benefit. While there are some interesting challenges in designing a (good) new file type to replace a collection of others, the big challenge will be getting enough buy-in from everyone in your problem domain to actually start using it. Without such buy-in, instead of having n different file formats, you'll simply end up with n+1 different file formats.
...roboticus
