This year (well, last year now) was my first attempt, and sadly I didn't make it. I had been doing a lot of writing at work, then work got busy, and a bunch of other stuff came up. I think after I got a day or two behind I got down, then I got stuck on a plot point that wasn't working (I didn't have a plot, basically) then figured ah well. Turns out I was past the halfway point and probably could have made it, but it was a first try and I'm not too bummed I didn't make it.
Now I don't even like the way I introduced the plot, so I'll have to change that, eventually. I'm still working on the story, here and there.
My best friend's done it several times, but I'm not sure if she's ever made it.