Still the development of MDT 2013 is hopelessly behind the technical preview releases of Windows. Until that happens you can still apply some custom hacks to the current version.
In Windows 10 Build 9926 you still need to add updated DISM files to the boot image (until the Windows 10 ADK is released), and due to the new "10.0.9926.0" version number, many of the MDT scripts, especially the LTIApply.wsf and ZTIUserStafe.wsf scripts has quite many string checks for "6.X" versions.
The problem is however that "10.0" is not higher than "6.2" when you do a string comparison. That means if you have a snippet that says:
If Left(oEnvironment.Item("OSCurrentVersion"), 3) >= "6.2"
Windows 10 will not fall into that If statement (since "10.0" is lower than "6.2" in a string comparison").
First, this is not supported so don't blame me if something is not working.
Update 2015-01-29: This post is only for plain bare metal deployment, to build a reference image see this post: Create a Windows 10 reference image using MDT 2013
In addition to have the the task sequence copy the right servicing stack to the WinPE 5.0 boot image you also need to use updated versions of some MDT 2013 scripts (click the link for download).
On your MDT server, copy the updated scripts to the scripts folder of your deployment share, replace existing files.
Also, copy the dism.exe and DISM folder from a x64 WTP boot.wim file to your deployment share, in my case E:MDTProductionToolsx64.
The dism.exe file and DISM folder are found in the X:WindowsSystem32 on your boot image (once booted), or E:MountWindowsSystem32 if you just mounted the boot.wim.
The needed files, copied to the deployment share.
After copying the files, add two run command line actions to your Windows Technical Preview task sequence (and only this task sequence).
Copy WTP dism.exe
cmd /c copy %deployroot%\tools\%architecture%\dism.exe x:\windows\system32 /y
Copy WTP DISM subsystem
cmd /c copy %deployroot%\tools\%architecture%\dism* x:\windows\system32\dism /y
The additional actions in the task sequence.