Difference between storing a DBUnit file in version control and using Liquibase for Database Version control?
From their own FAQ:
"Can I use DbUnit in order to check and execute DDL statements?
    No. DbUnit is not intended to track or test structural DB changes. For this purpose check out liquibase."

So it appears that DbUnit is useful for storing data differences between different versions of a database, while LiquiBase is for schema changes.