When it's done.
Trust me, you don't want to know how messed up my life is right now and how many other things I have to do, not to mention occasionally lacking in inspiration. For a while there I was writing a story every week. Then it was suddenly several months with nothing. I do the best I can, but sometimes I just can't deal with trying to keep this on schedule.
On the other hand, sometimes I just get distracted and can be prompted to hurry up a bit. If you ask for a progress report on the messageboard, I can probably let you know whether it's "coming along" or "going to be a while".
But don't worry that I'm just going to stop posting - while I may not have the story arc planned out in detail that far in advance, I know of at least two *major* events that aren't going to happen until "season three". This series will be going for a while.