Exchange 2003, Sever 2003, and SBS 2003

We currently have one SBS server thats the domain controller, active directory, exchange, sharepoint, database services, and file storage. I’ve started to setup a Server 2003 server and I would like exchange and sharepoint to be on the new server. Will this work without scrapping the existing SBS server? Can I just install exchange on the 2003 server and then migrate the mailboxes over?