Thanks Mike,
The power cable was put in back in March and connected at that time (I went past as the electrician was connecting it into the isolation switch in the left hand side panel of the cabinet). But it has never 'hummed' until today.
I'm guessing that they have actually commissioned it now and switched it on as part of that process, but as none of the cabinets on my exchange seem to be accepting orders yet i'm guessing there is still something to do at the head-end.
***EDIT***
Just checked a telephone number for a business off another cabinet and it is now showing as available

So it seems my cabinet needs to be added to the database....
***EDIT***
Have checked several locations on various cabinets around Epping now and it seems the cabinets that went in first are now live and accepting orders, but there are some that went in a bit later (including mine) that are still showing as 30 June.
The fact that my cabinet started humming today and the other cabinets are now showing as accepting orders cannot be a coincidence - will keep checking the checker to see if it gets added (wonder what the lead time between commissioning and database update is?).
Edited by Colin_London (Tue 22-May-12 00:58:52)