With all the recent talk about the future of metadata on MacOS, I thought I'd share this little story; forgive me if this is common knowledge:
Working in OS 9, I exported an EPS file out of Quark and imported into Photoshop. To my surprise, it wouldn't parse the file, reporting something along the lines of "Incorrect JPEG marker-- file is incomplete or corrupt". Inspecting the file, I realized that I had accidentally saved the file as "poster.jpg" instead of "poster.eps" (I always use extensions, for my own ease of organization). When I changed it to ".eps," it opened without a hitch.
What this means is that Photoshop had ignored the type/creator codes (which were EPS) and was preferring to look at the filename to determine the file content. This is not how macs are supposed to work.
So forget OSX; we've already lost the metadata battle (not that I'm suggesting we give up. Sign those petitions!)