Some of the Optim tools are already included in the AESE and on the engine side data compression (tables, indexes, XML data, temporary data), HADR and Q-Replication for realizing your high availability and disaster recovery solution of choice, label-based access control (LBAC) for greater data security, and data federation for DB2 and Oracle databases are some of the features that are part of the bundle.
And if you wonder: pureXML is always included free of charge, even in the free Express-C edition of DB2.