As for me personally, I'll definitely be sticking around. I plan to continue writing in this fandom for a good long while. It is fairly inevitable that one day I will move on to something else, or will lose interest… but that would have happened anyway. I walked away from The X-Files when it still had several seasons to run, after all. (And that felt awful, by the way – to watch people leaving in droves from a show that was still running.)
Fandom is forever changing. For everyone who thinks the current season is the best yet, there's that person who stopped watching in season two. For every new fan, drawn by DVDs, there's the old fan whose imagination has been grabbed by some new show. For me, personally, a show being current or not bears little relation to my own enthusiasm. In fact, sometimes I love it more when it's gone, since I can love it unreservedly, without worrying that favourite characters are going to be killed off or have their screen time reduced, or that the story arc is going to go in directions I dislike.
The lack of new episodes will mean that I am no longer getting anything new from the show to spark fanfic ideas, but for every cloud there's a silver lining. At present, I feel a bit awkward about writing stories set back in season one, because it feels like running away from the present. Once the show's finished, everything is past. Everything's fair game. As I said in my post on canon, I'm very wary of committing myself on anything – character backstory etc. – that might be contradicted by future canon, but once there is no future canon, we can do whatever we like. It's quite liberating, really.
One thing that will definitely be affected, though, is my plan to give up writing during September. With only four months of "live" fandom left, I want to make the most of every week. I'm still planning to write a little less obsessively and I'm definitely planning to read lots and lots of fanfic and send lots and lots of feedback, but all the rest – novels, computer games, DVDs etc. – can wait.
Oh, and I did consider taking a few days off posting On the Road to Come What May, on the grounds that no-one would be in the mood to read it, but I decided not to second guess people. For everyone not able to face fanfic there was probably someone eager to escape into it, so I decided to go ahead as planned.