I finally got around to reading the preliminary SharePoint 2010 taxonomy and metadata info on MSDN. As most of you know, MOSS 2007 had some serious challenges in this regard (e.g., no hierarchical metadata, no sharing controlled vocabularies across site collections, etc.) -- and they caused information architects like me much consternation.
It would appear that SharePoint 2010 includes many new features under the umbrella of Enterprise Metadata Management, and they seem to have addressed some key issues. Here are the highlights.
1. Terms & Keywords
SharePoint 2010 has a few types of vocabularies with different levels of control:
Terms: Basic construct -- a word or phrase that can be associated with content. A term can become a managed term or a managed keyword.
Managed Terms: A controlled term that can only be created by those with appropriate permissions. Term sets (think of them as taxonomy facets) are collections of related terms that can be hierarchically structured.
Managed Keywords: User-generated keywords (aka tags) kept in a non-hierarchical list called the keyword set.
What's nice is that you can easily turn a managed keyword into a managed term, which essentially sets up SharePoint 2010 as a decent platform to blend taxonomy and folksonomy approaches (more on this later).
2. Managed metadata & the Term Store
Once you have managed terms in place, you can create a new column type called "managed metadata". This column type is like the 2007 lookup, but points to the managed term sets instead of lists.
One of the biggest limitations of MOSS 2007 was the site collection boundary: lists were specific to a site collection, so in order to share metadata and taxonomy across multiple collections, you had to essentially reproduce the same lists in each collection.
Managed term sets (and managed keywords) now live in what's called the Term Store Management Tool -- a centralized database that allows term sets to be shared across a farm.
SharePoint 2010 -- Centralized Metadata Repository. Image courtesy of EndUserSharePoint.com.
3. Taxonomy & Metadata Management
Within the Term Store, there are some metadata and taxonomy management functions enabled, though the documentation is not clear on how many of them are achieved.