Every mobile platform contains several different chips, to handle different specialized tasks. The "dual-core ARM" is not two ARM11 chips, as one might imagine, but rather a single ARM11 (at 600 MHz) and an ARM9 to handle the radio baseband communications (e.g. not for user tasks). By that standard, every mobile processor is "multi-core."
Qualcomm MSM7200 (with integrated ARM926EJ-S Coprocessor@274MHz <-----