As I just tweeted, I'm pretty sure I'll hit 50K, but I won't feel like a winner unless I type "the end".
I have eight chapters blocked and unwritten. Maybe I'll get my certificate, but I won't print it until I'm done. I may run to 70K. I would hate to lose the drive that I've had to finish this, and if I stop at the end of November, I'll have 60K.