Content type syndication feature is amazing feature in share point 2010.This feature enable to centralized management and publication of content type. One of the scenarios where we can utilize this feature is when we need to maintain policies attached to the content types globally. In share point all the data structures are implemented as List and this lists are composed of content types. Content types are powerful data structures in share point where you can attached event receivers, work flows, policies etc.
Share point 2010 allows metadata management globally. For this one of the Site collection in the farm need to be act as the centralized location. This location is called content type hub in share point 2010 environment. Share point 2010 limits only one content type hub across the farm. Once the content type hub is set up, any number of content types in this hub can be a candidate for publishing. Once content type is published it can be accessed across the farm in any site collection, as they are globally available content types.
The settings for a content type hub can be initially done in the central admin using UI, however if we plan to change the content type hub we need to use power shell script for it. The content type publishing is carried out by timer jobs. So the scheduling of this timer jobs and their frequency are subject to be determined while planning the change propagation of the existing content type to its subscribers. A content type can re-publish any number of times for changes.
Content type syndication feature is very use full for implementing document retention policy across the farm. When workflow is attached to the content type which is candidate for publishing, And the target site have the same workflow. The workflow will be associated to the subscribed content type. But when a content type is published default no workflow associated with it is published. The only required thing is the required workflow to bring up in the subscribed site. The content type syndication will automatically take care of associating with the workflow in the subscribed site.