I have the same understanding as MNBlockHead.
With the content market fully rolled out we should be able to:
- Buy and integrate commercial content into our realms.
- Make whole or parts of our own realms available for others.
- Take whole or parts of one of our realms and integrate into other of our realms.
And (and I hope I have understood this right):
- Make a master realm; any changes in this realm will be synched to one or more child realms (for want of a better term) while changes made in the child realm will not be synched to other realms.
The last one will be a very strong feature.
Again, this is my understanding.