Hello ,
I assume you are planning to migrate UC apps from MCS to UCS servers.
From UCS /VMware perspective, you can have the VMs ready by deploying UC OVAs and installing the necessary software. If you are using other server hardware running ESXi, here are the supported VMware features on migrating the VMs
http://docwiki.cisco.com/wiki/Unified_Communications_VMware_Requirements
Supported hardware for virtualizing UC apps
http://docwiki.cisco.com/wiki/UC_Virtualization_Supported_Hardware
In general, there might be requirements from UC apps and would suggest you post it in Voice forums on best practices.
Here is one preso on platform migration.
https://www.ciscolive365.com/connect/sessionDetail.ww?SESSION_ID=3253
HTH
Padma