I did bring my NaNo project to a screeching halt. It was the right thing to do. I'll be writing again by tomorrow afternoon, but with the advantage of a legal pad full of character notes so I don't keep on contradicting myself.
Some stories are single POV with straight forward plotting. It's easy to go from A to Z at 80 words a minute and exceed that 50,000 NaNo word count with relative ease. That was my 2011 NaNo experience, and it was good.
I bit off more than I could chew this year, however, by plunging into two parallel stories with lots of characters. The stories will come together in the last third of the novel, so the characters' timelines are critical. When I thought of later trying to revise and rewrite that 50,000 words of random and unorganized writing, I caved.
I'm fine with my decision. I'll still post my word count through the end of the month. Even if I have 30,000 words of a new novel, I'll be a very happy writer. Thanks to NaNoWriMo, I feel like I'm back on that carousel for another ride.