The recent leak of Windows 8 Milestone 1 Build 7850 has been given more features via registry hacks. The features are still under development, so I am sure they are not 100% stable and ready for release.
Here is how to enable the following features:
To unlock webcam.exe
Navigate to “HKEY_LOCAL_MACHINESoftwareMicrosoftWindows NTCurrentVersionGRE_Initialize”
create a DWORD value called “RemoteFontBootCacheFlags“, set its value to “0x100f (4111)”
To unlock Modern Reader
Navigate to “HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurr entVersionAppletsPaintCapabilities” create a string value named “CLSID”, set its value to “{D3E34B21-9D75-101A-8C3D-00AA001A1652}” , then run glcnd.exe.
To unlock the new Task Manager UI
Navigate to “HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionTaskUI”, and create a 32bit value “TaskUIEnabled“, set its value to “1”.
And finally, to unlock the ribbon UI in Windows Explorer
Create this key in the registry: HKEY_CLASSES_ROOTCLSID{4F12FF5D-D319-4A79-8380-9CC80384DC08}
Create a string value called “AppID”, set its value to “{9198DA45-C7D5-4EFF-A726-78FC547DFF53}”
Restart Explorer and you should have the ribbon UI unlocked.