The Shared Service Providers are disappears, now SharePoint use „Service Applications“. Service applications, as the name let you suppose, provides several services for your Sharepoint envriroment. One web application is not constrained to use a dedicated Shared Service Provider furthermore. Web Applications now can consume several service applications from the same SharePoint farm or another Sharepoint farm. Therefore, service applications can be a endpoint provider. This makes many new topology scenarios availible for SharePoint 2010 scenarios ( TechNet ). Per example, you can build a „Service Farm“, shown in the figure below.
The arrows should show you, that the „Staging Farm“ and the „Productiv Farm“ consume from service applications of the „Service Farm“. This allows to use the same taxonomies in every farm, per example. Or (and this is my favorite at the moment 🙂 ) to push central stored Content Typs to every Farm in your envriroment.
Chak Corner described the configuration for „Content Typ Hubs“ in a blog post in detail.
Have fun by playing with service applications by yourself for the first time!