Indeed, no more COS for ESX4, actually no more ESX4 but only ESXi
VMware ESXi is the next generation hypervisor architecture from VMware, offering improved reliability, security, and a simplified operational model. Due to the superior nature of ESXi, VMware will discontinue the classic Service Console-based ESX in the near future. If you are a long-time user of ESX and have developed your management procedures around the Service Console, then come to this session to learn how to migrate to a new, improved operational model. We will show how to adapt your process for all aspects of management, including: hardware monitoring, backup, systems management, user management, logging, troubleshooting, and more. You should be able to leave this session armed with the tools necessary to be prepared for the transition to ESXi.
What is this session VMware is talking about!? Well is being held at VMworld2009 and unfortunately the session is far from free 😦