If you filed a bug against shared-mime-info in the past and wonder why your requested mime-type still isn't in, it's just a lack of time, and the fact that most of the bug reports require too much work on my side to be integrated.
If your bug doesn't include a test case, I won't look at it.
If your bug is a copy/paste of a stand-alone mime definition file, I won't look at it.
If your bug doesn't contain any reference information, I won't look at it.
If your patch isn't git-formatted, I won't look at it.
If your patch breaks the test suite, I won't look at it.
Given the requirements to compiling shared-mime-info (git, a C compiler, and glib), I don't think I'm setting the barrier too high. Furthermore, all those requirements are spelled out in the HACKING file.
Let me know if you have any questions, or want clarification on some points, so I can update the HACKING file with that information.