You may have caught wind about a particular feature of ConfigMgr 2012 called Shared Distribution Points. It's worth noting that this component is ONLY for migration purposes from a ConfigMgr 2007 environment to a ConfigMgr 2012 implementation.
When doing a side-by-side migration (the only option to migrate, btw) from CM2007 to CM2012, CM2012 can utilize the Shared Distribution Point so that clients can still be managed during the process. These Distribution Points are only shared when the ConfigMgr 2007 environment remains the active hierarchy and the distribution point is configured for sharing. When you finally flip the switch completely to CM2012 and your old 2007 hierarchy is no longer managing any endpoints, the Distribution Point is no longer shared.