On Halloween and Christmas Sony stated that special content will be made available, only for a limited time though. Could we be seeing Halloween costumes for our avatars in October? Perhaps a Santa Clause avatar in December? The possibilities are endless.
One thing which Sony did state though is that Home is not a persistent world. This means that once you leave Home all of your possessions will go with you. This means that once your PlayStation 3 shuts off and you are disconnected to the network no friends can visit your Home Space.