Yesterday IBM GAed the IBM Mobile Database, a special database for Android devices. The IBM Mobile Database works with the solidDB Sync Server to bring your enterprise data from DB2 or Informix databases to a mobile device (and back, of course). Thus, the title should actually say DB2 data on Android...
The IBM Mobile Database is free of charge and supports an SQL API. It is suited to build your own mobile database applications on top. These applications would be able to directly, even with transaction support during connect loss, work with data coming from a central enterprise database.