I think the folks at a few of the bigger vendors of Poser content, like the owners of Renderosity and DAZ should agree on a document outlining the basic configuration of content.  If they did, most of the other vendors would fall into line I think.  There could be an open license, allowing artists to add a trademark or seal of approval or whatever to tell customers they'd made the minimal effort necessary to comply with standards.  It would be easier for artists, really, because they'd have guidelines and wouldn't need to make as many decisions when creating content.  And it would sure as hell simplify the lives of their customers.

For example, the easiest structure that springs to mind for me for non-library files is content type>Vendor>Artist>[below this level is at discretion of artist].

For library files, things get a bit trickier since they need to be a bit more finely tuned.  Maybe default folder (character, pose, hair, etc.)>category*>Vendor (optional; needed more for vendors like DAZ)>Artist>[Artist's discretion]

• category depends on context; for character folder you'd obviously need quite a few categories like figures, clothing, hair, gear (worn or carried, non-clothing items), objects (other items), scenes (structures, etc.), utilities, etc.

"Content type" really means "depends on context" here.  E.g., geometry goes in the geometry folder, morphs go into the morphs folder (btw, isn't the morphs folder created by default inside the libraries folder in P7?), etc.

Personally I prefer that artists put each product in its own folder, with EVERYTHING NAMED INTELLIGENTLY (or at least uniquely), but I realize that may be a bit much to ask, and it might be better just to give suggestions for best practices beyond the level of the Artist's "root" folders (e.g., the artist's name, and the product name, should be on every file (but not necessarily folder).

I don't know all that much about naming conventions myself, other than what common sense and experience tell me works for me.  But I DO know that more is better than less when dealing with "broadcasting," where one person's efforts during creation dictate how much work the far greater numbers of customers will have to deal with after purchase.  E.g., if an artist is a schmuck and names his shirt "shirt," and puts the library files right into the character folder, he's pretty much guaranteeing that all his customers will have to at least create a new folder, maybe as many as three, and maybe rename the thing.  This gets old fast; one person's laziness and lack of forethought have dictated that x people now have to do the work he didn't do.

My own library folder structure is very different from what's outlined above, but if there was any kind of standard I'd probably just go with it and be satisfied; it's the total lack of any kind of sensible standard that forces me to roll my own.
I'd be willing to discuss the details of something like this, if the parties mentioned above were willing to support such a document, but not put in the work creating one.

I know the main argument against a standard for library content (no good  argument against standardizing non-library folder structures, like geometry, that I can think of ATM) is that every customer has his own preferred structure, and no standard could ever possibly keep them all happy, but at least a standard would give him a consistent place to LOOK for things in the first place when he goes to sort his library folders.

Just an idea.  :)