Update: Microsoft has released CU2 for Configuration Manager 2012 Service Pack 1, allowing you to use Boot images based on Windows 7 from the WAIK again (with some contstraints but workable). See the KB 2854009 article for more information. See this article written by Brandon Linton from Microsoft for more information on how to import your WAIK boot image: How to Create and Import a WinPE 3.1 Boot image for use in ConfigMgr 2012 SP1 CU2
VMware’s vSphere 4 doesn’t and will not support running Windows 8 and Windows Server 2012 as a VM on top of its ESXi hypervisor. The reason for this is that the BIOS for the VM’s running on top of vSphere 4 do not meet the Windows 8 Hardware Requirements. You can check vSphere compatibility for Microsoft Windows 8 here. For ConfigMgr this shouldn’t be a direct problem, because we can still install the ConfigMgr roles on top of Windows Server 2008 R2.
When installing ConfigMgr 2012 SP1 or upgrading to SP1, one of the changes introduced is that the Windows Automated Installation Kit (WAIK) isn’t used anymore, and we start using the Assessment and Deployment Toolkit (ADK). And this is were we have a potential issue, because the ADK contains a new boot image based on Windows 8 which will be used to create the new Boot images.