SharePoint 2010 comes with some wonderful managed metadata features. A quick Google search returns oodles of information about planning your managed metadata, adding managed metadata columns to lists and libraries, and using metadata navigation. What most of them fail to point out is that there are features that need to be enabled in order to use the managed metadata columns and the metadata navigation. Those features aren’t exposed in the UI in an out of the box configuration.
After much spelunking and blog reading and traipsing through the SharePoint root directory, I finally figured out how to enable these two features. Using the SharePoint 2010 Management Shell (PowerShell), you simple run the following commands:
Enable-SPFeature -id "73EF14B1-13A9-416b-A9B5-ECECA2B0604C" -Url <Site-URL>
Enable-SPFeature -id "7201D6A4-A5D3-49A1-8C19-19C4BAC6E668" -Url <Site-URL>
The first one is the feature that allows the use of managed metadata columns for libraries and lists. The second one is the one that adds the metadata navigation options (and filter keys). Technically, the second feature isn't listed as hidden and so it should show up in the UI. But, in my development install, it did not.
As a side note, when you read about features that aren't showing in your UI, and you want to track them down, head on over to your SharePoint feature directory, which is typically:
C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\FEATURES
Find the subfolder for the feature you are interested in, and find the Feature.xml file within. Open it with a text reader, copy the ID for the feature, and plug it into the commands above. Run it and you'll be able to install any of the hidden features.
Hopefully this will save someone else a major search hassle.