Last? Let's say latest. But in truth, I don't see W1S1 in my near future. I had planned on giving a few excuses involving my hectic personal life, but I don't need excuses, I need reasons, and the reason I'm taking a break from W1S1 is because I just don't see the same quality in my W1S1 stories that I see in my other writing. I re-read "The Machine last night and found that it's better than anything I've written in months. Not that the idea is necessarily better than, say, "Summer of Change," but it's more polished, has a better narrative flow. There's a voice that I don't have in the other work. It's no coincidence that "The Machine" has been revised (not rewritten; revised, polished) three or four times.
I'm not a quick writer, and I've found that the longer I stay in the challenge, the more difficult it becomes to meet the deadlines. I moved from the monthly to the weekly challenges because I thought it would light a fire under me--which it did--but ultimately the same thing happened, and I spent more time worrying about getting done than getting it done right.
Things could change, of course. They usually do.