SRM version 4 had officially released and ready to download from VMware Official Website. Before this, users with SRM will not able to upgrade to vSphere 4 due to the SRM compatible. Now you will be excited to upgrade your existing ESX 3.5 to vSphere 4 with SRM 4. You can read more about SRM 4 from here. You can download the latest copy of SRM 4 from here.