A new feature of Sharepoint 2010 is the ability to publish content types to all web application and site collections from a centralized Content Type Hub.
For more details about Content Type Syndication and with code example you can visit this url http://msdn.microsoft.com/en-us/library/ff394469.aspx.
To activate Content Type Syndication on Sharepoint 2010 follow the instructions below:
Go to Central Administration and under Application Management click on Manage service applications.
On Service Applications page locate and select Managed Metadata Service then click Properties button from the ribbon toolbar.
On property window enter the URL for the site collection (Content Type hub) from which this service application will consume content types then click Ok button to complete.
Select Managed Metadata Service on Service Applications and click on properties from ribbon toolbar.
Check “Consumes content types from the content type Gallery at …” from the Managed Metadata Service Connection property.
Now you can login to Content type hub which you defined from the above instruction.
Go to Site Settings > Galleries > Site Content Types click on one of the content types listed and notice that there will be a new link Manage publishing for this content type, click it.
Now you have the ability to publish content types to all Web Applications and Site Collections cool!
