In XP SP3 and vista SP1 there is no such switch, and now you have to use the /admin switch.
To me, it seems pointless but on the internet they claim that this is due to an architectural change in the Windows Server 2008. Session 0 is not an interactive session, it is only used for services, and this way /console session is not different from any other session that is connected to Windows 2008 terminal services.
The /admin switch is now used to access only a session which is free of Terminal Services CALs.
