Maintaining a central term store has obvious advantages, but using that term store for your User Profile Service (and hence the data in your My Sites) isn't exactly straight forward. The basic steps are
1. Make sure the User Profile Service is running correctly on the consuming farm. We don't want to consume the User Profile Service of the publsihing farm in this case because we want to have a My Site host on this farm.
2. Create a connection to the Managed Metadata Service. You can do this by following these instructions http://www.sharepointninja.com/Blog/Lists/Posts/Post.aspx?List=1b1adaf0%2Dd914%2D4578%2D9613%2Df33ce22c41fe&ID=44&Web=9a7fbd73%2D9558%2D4b79%2D80c1%2D194bde406be0 (replacing the User Profile Service with Managed Metadata Service in the instructions)
3. After you have created a connection, go ahead and create a Managed Metadata Service Application on the consuming farm. Therefore, there will be two instances of the Managed Metadata Service (one running on the consuming farm and one connection to the publishing farm).
4. Double check to make sure the Managed Metadata Web Service is running on the Manage Services on Server page in Central Administration.
5. Make sure the local Managed Metadata Service Application is associated with your My Site Host web application.
That should be it. Now when you go to modify the User Profile Properties the term store sets should show up as options for you to tie your fields to. Thereby keeping all the data happy and in synch.
-Michael
Twitter: @SharePointNinja
#sharepoint
#ManagedMetadata #SharePoint