Okay, you have set up your content type hub, published your content types and are now ready to use them in your lists and libraries. You go to your list, click to add from existing content types and your published content types aren’t available.
You may find this if the top level site in your site collection was created from the Blank Site template (there may also be other templates out there where this doesn’t work too). This is because the TaxonomyFeatureStapler feature does not include the Blank Site template.
You probably don’t want to go back and recreate your site collection again, so you can activate the feature manually by typing the following stsadm command:
stsadm -o activatefeature -id 73EF14B1-13A9-416b-A9B5-ECECA2B0604C -url http://toplevelsiteurl
Once activated, you will see the Content type publishing option appear in Site Collection Administration, as well as the Term store management option in Site Administration on the top level site. You should now be able to use your published content types as required – even in sub-sites (if not, you can repeat the stsadm command for your sub-sites, too).