Content Type Hubs or centrally managed content types were one of the biggest (and under appreciated) additions to SharePoint 2010. When working with several web applications and site collections (which is inevitable most of the time), keeping content types up to date over several location can become a drag and easy to make mistakes. So Microsoft added the possibility to have a centrally managed hub, were site collections and web application can subscribe to and still have local content types.
As Office 365 is based on the SharePoint 2010 framework, The Content Type Hub is available to be activated as site collection feature. But beware! On a SP 2010 server, we can activate the feature for any web app/site collection. This way you define one or more web applications/site collections as content type hub and name them appropriately. This can not be done in Office 365. You receive 1 Content Type Hub which is by default https://[account].sharepoint.com/sites/contenttypehub and this is "by design" (in case you were wondering). Yes, you have the option in all web applications and site collections to activate the content type hub, but it will not work! You will found only after you're done with setting it all up (Technet: Configuring the Content Type Hub), creating the content types and getting ready to start the sync. The moment you are settings subscriptions, you will find out that you can only get 1 subscriptions, which is the default /sites/contenttypehub.
In short you receive the Lite version of the Content Type Hub in Office 365. So make sure when planning your Office 365 infrastructure, that you only have 1 Content Type Hub and it's available to you only at the default location. I found out the hard way, so you don't have to :)