ESX Server - End of Life Announced!

Finally after almost a decade since its first release, and three years after ESXi was introduced, ESX Server product has an end of life date. The days of debating with IT folks that ESX is "Linux based" has finally come to an end. VMware, with the release of ESX 4.1, very quietly announced that this would be the last version of ESX Server, with its legacy Service Console (or COS). Future versions of VMware's enterprise class hypervisor will ship only in the ESXi version.
To be honest, it was VMware's early releases of ESX Server documentation which did not differentiate between the hypervisor and the COS. At the time, the term “hypervisor” was largely unknown. Come to think of it so was the term "server virtualization" and no one understood what a “virtual machine” was. But as the years went on and ESX Server became the hypervisor standard in the industry, it also became very clear that ESX Server was not a "Linux based" operating system. Instead, ESX was the hypervisor and the “server part” was a virtual machine that was used to manage and configure the hypervisor. It was this virtual machine that actually was a Linux operating system (a stripped down version of Red Hat Linux). Still though, this architecture was a difficult discussion when you ran into organizations that had a "no Linux" rule.
After the release of ESXi in 2007, the “Linux-less” version ESX Server was very slow to be adopted in part because its initial release was not fully compatible with VMware's Virtual Infrastructure (now known as vSphere). This lack of compatibility with ESXi only fueled the belief that the server piece of ESX Server was not just a VM for management instead it was needed for the hypervisor to perform some of the advanced virtual infrastructure tasks.
Finally, after years of ESX rumors regarding VMware’s removal of the legacy COS, that reality will finally arrive with ESXi's next release. The days of unstable, third party Linux utilities running in ESX Server’s COS have come to an end. Anyone still using ESX Server because of custom agents or scripts in the COS will have to finally move to a solution that supports ESXi.
For those of you that are still running your infrastructure on ESX Server, don’t worry. You still have some time before ESX Server is retired. VMware has delivered many tools and utilities to help you migrate to ESXi. They have even gone as far to develop a two day training class to help you migrate any lasting dependencies that will prevent you from upgrading to ESXi.
http://blogs.vmware.com/vsphere/2010/07/esx-41-is-the-last-esx-what-do-i-do-now.html