HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Terminal Server\CentralPublishedResources\PublishedFarms\<collection>\RemoteDesktops\<collection>

ShowInPortal     REG_DWORD     0x00000001 (1 means SHOW the desktop connection icon, 0 will hide it)

WS2012 VDI TIP: How to Publish a Full Desktop Alongside Published RemoteApps