This info might be subject to change in final release. This blog focuses on CPT2.
Support for network virtualization was introduced in CTP1. The CTP2 release adds support for using DHCP to assign customer addresses, and for using either the IP rewrite or Network Virtualization with Generic Routing Encapsulation (NVGRE) mechanism to virtualize the IP address of a virtual machine.
Support for VHDX was introduced in CTP1. In the CTP2 release, you can convert a virtual hard disk format from .vhd to .vhdx, there are placement enhancements to determine the format of a virtual hard disk based on the operating system of the destination host (when you create a virtual machine with a blank virtual hard disk), and the provisioning of a physical computer as a Hyper-V host supports the use of a .vhdx file as the base operating system image. Additionally, you can use VMM to rapid provision virtual machines that use VHDX-based virtual hard disks from SAN-copy capable templates.
The CTP2 release adds support for the new Windows Standards-Based Storage Management service, which uses the same WMI-based programming interface that is included in Windows Server 2012. This new API enables you to discover storage by using multiple provider types. In addition, the CTP2 release adds support for the thin provisioning of logical units.
The CTP2 release adds support for using a virtual hard disk that is in the .vhdx format as the base operating system image, and for performing deep discovery to retrieve more detailed information about the physical computer.
The CTP2 release enables you to create user interface (UI) extensions for the VMM console.