Prior to update, I had the system set up so that turning on the DK2 would turn off my primary monitor and set the refresh rate to 75Hz. After updating, I was never able to get the system to detect the DK2 at all, either through the Oculus runtime or the multi-monitor display options. After wading through some old oculus forum entries relating to SDK 0.5, it looked like windows was automatically assigning a default monitor driver to the DK2. This driver would then fail and the DK2 would never start up.
So, I made up this procedure to clear up the registry. Please bear in mind that interfering with the registry as a system level user is extremely risky. I backed up my system before going through with this and had to restore it on my first attempt at the process. So please note that I most likely won't be able to help if you toast your Windows install. I did this on a backup machine that literally has only Elite, the DK2 and some other games installed on it.
1. Uninstall all Oculus software.
2. Download a utility called PSEXEC (which can be found on Microsoft's technet).
3. Open a command prompt as an administrator, navigate to the folder where you put psexec and run the command "PSEXEC -i -s -d CMD"
4. In the new command window type "regedit.exe".
5. Look for registry entires containing "OVR0003" and remove them. If a folder contained only references to the OVR0003 display, I also removed that folder.
6. Cross your fingers and restart the system.
7. Install SDK 0.5
After doing this, windows was able to detect the DK2 as a second display and I could configure it as before. I was also able to get windows to automatically switch to the DK2 when it is powered on and return to a monitor when it is switched off. I haven't tried the SDK switcher yet. Elite worked fine after I had set up the desktop to display on the DK2.
Again, good luck if you try this.