I notice that after my "massive" brain dump of several days ago, that I overlooked to follow up on some of Karrie's questions. First and foremost: No I have not seen anything like the level of sophistication I describe here. I was quite involved in a similar community rating scheme developed with input from the community, but the archives from that project have been taken down from the Internet. To cut to the chase, I think this would be a "pioneering" scenario.
I have also run the the ideas through my "database" perspective -- and I must say that it is indeed very complex -- especially if some members are permitted to have "personal" tags (so I would perhaps limit this quite strongly).
I would say that the crux of the "tagging" system (I am going to stick with this term -- the descriptors actually function quite similarly to "tags"... indeed, so similarly, that it might be useful to think of the data architecture in similar terms [but that need not worry us here]): let's say the "community wide" vocabulary contained, say, 20 - 40 terms. For "information retrieval" (aka "search"), this would be the number of "types" the search engine would have to check, tally up into a score, etc. -- resulting in a rating such as "very funny" or "quite insightful" or "super helpful" (in these examples, the terms would be "funny", "insightful", "helpful"). IMHO, there is no reason why the same principle might not equally apply to such descriptors as "marketing", "accounting", "teamwork" etc. (but it might nonetheless be useful to differentiate between articles that are funny / helpful and articles that are about how to be funny / helpful.
Here are some more concrete suggestions -- I would suggest three "levels":
0: Basic membership
allows members to choose e.g. 4-6 terms to tag from palette of community-wide terms
1: Active membership
allows members to choose e.g. 6-8 terms to tag from a palette community-wide terms (terms may be "freely" assigned until the community-wide vocabulary is "filled")
2: Supporting membership
allows members to choose e.g. 6-8 terms to tag from a palette community-wide terms plus 1 freely chosen term
The availability of freely chosen terms means that the language will predominantly be shaped by active+supporting members, but every member will still be "free" to apply his/her chosen terms as he/she feels is most appropriate.
Some might find it "quirky" that it might be "necessary" to have 2 levels of vocabulary (community-wide vs. selected terms). What is really going on here is that this helps members to focus on what they feel is most important from their specific expertise (or "point of view"). So whereas I personally may not be an expert at deciding whether something is "world-changing" or not (and perhaps I might not care, either), but I may instead look for whether something has the attribute "promotes social cohesion" -- and if that is something I feel strongly about, then I might choose that as an attribute to "rate" things. So the point of 2 levels is to allow what might be referred to as "linguistic relativism" -- like Eskimos have many words for "snow" vs. Germans have many words for "beer".
Well, I guess that all sounds quite abstract (and I guess it is abstract).
One simple approach to "get the show on the road" in a simple / straightforward manner would be to simply start out allowing every user to use up to 4 tags and the community-wide vocabulary would "fill up" at say 40 terms. Then, at that point, only the 40 most popular terms would be maintained (and if someone had selected a term outside of this vocabulary, it would then be set to "undefined", "nondescript" or something like that).
This simpler approach would perhaps be a way to "kickstart" such an approach without introducing alot of complexity. Later, this could be refined to add such "bells and whistles" as providing methods for allowing the language to "evolve".
OMG -- I didn't want to write this much! :O
Sorry again -- I will have to practice being more succinct (if at all possible?)...
:) nmw