Ha. I wrote a pretty thorough outline by using a couple of sentences per scene to describe what was happening. Then I got to the end and left it blank thinking that I'd finish it when the time came. Well, the time came and I had no idea how to finish in terms of sequence. One thing though, my initial ending was a piece of crap. It took me months of writing to think up a more suitable alternative. Outlining for sequence is wonderful, not so much plot.
So what I'm trying to say is, don't dwell on an unfinished outline. Odds are that many things will change along the way. Get a pretty solid outline and follow it loosely. By the time you are finished writing all the point in your outline, you've already figured out an ending.
I'm pro outline, but to an extent. Don't follow it religiously. I highly recommended it because it allows you to focus and not have to worry about what happens next. It increases your odds of actually finishing a manuscript by like 40% or something. Okay, that percentage is totally made up, but those who have some sort of outline tend to accomplish more than those without one. Even a partial outline is great.