At VMworld Europe 2009 breakout sessions on the products listed below will be held. Guess those products are the first to be released being part of the Virtual DataCenter   OS.

It is unclear if ESX4 also known as vSphere will be released. My guess it will be released at VMworld USA.

 

vCenter Server Heartbeat 

vCenter Data Recovery
vShield Zones
vCenter Chargeback

vCenter CapacityIQ
vCenter Orchestrator
vCenter ConfigControl

vCenter AppSpeed

vCenter Server for Linux