Integrating Hosted with Self-Hosted WordPress?

We have a client (Recording artist) who has a hosted wordpress blog. It works well for him because of the amount of traffic he gets from the wordpress.com community. However we are considering moving him over to self-hosted WP in order to take advantage of plugins, etc. How can we do this without loosing the hosted traffic? Is there a way to integrate hosted with self hosted? Can a hosted blog be “wrapped” into a self hosted wordpress website while enabling the use of plugins?

Any ideas or advice is much appreciated.

Cheers
James Pew