It can be really frustrating to have a story completely written, and still be struggling over the title. With no title, there's no cover either. Granted, you could probably play around with some cover ideas based on the story, but often those two things tie together, at least in my mind.
And so, my NaNoWriMo story continues to be without a title, as I play with a variety of ideas, trying to find one that grabs hold. I have another story that I have the full outline for, and am about 1/3 through writing, and it's already had 2 titles, and I'm still not satisfied. I'm hoping I don't get backed up too much on untitled stories, but I guess that's better than having titles without stories, lol.