I just tested the new patch attached to http://bugs.freedesktop.org/show_bug.cgi?id=24690#c1
My .ts-Files indeed all start with 0x47. But after the patch is applied, all files that start with 0x47 are "video/mp2t", even if their filenames do not end with ".ts". I have here .ts-files that come together with meta files with same name but different suffix. Some of these meta files incidentally start with 0x47, and hence are treated as videos too.
I'd prefer that files are "video/mp2t" only if they start with 0x47 *AND* their filename ends with '.ts' (or '.mp2t' or '.mpts' or '.mpg' or other suffix that might be common for mpeg transport stream files).