I encourage everyone interested in NaNoWriMo to give it a try. Most years I just used it as an excuse to edit my existing manuscripts, but last year I decided to do it properly and start a new book. It came down to the wire, but I managed to reach the 50,000 words before the deadline and it was a hugely satisfying experience. And, even if one didn't reach the goal, they would still have more of a novel than they ever had before. I think that's the true value of NaNo; giving yourself a deadline and producing more work than you would have normally.