I wouldn't recommend a ultra-low calorie diet, from personal experience it ends up a lot more trouble than it's worth. At your current weight I highly doubt you'd plateau anytime soon (maybe after a year or so) but you would most likely be damaging your metabolism.
When I first started last year I didn't really know about calories and basically my lifestyle change involved cutting out all junk food, soda/juice, candy, sodium, fast-food, ... . I limited myself to 3 sensible meals a day with no snacks. I didn't weigh myself but I went from a tight size 24 to 22 in about a month (I'm guessing 25+ lbs). After about 6 weeks or so I started getting frequent dizzy spells and even blacked-out a few times. A trip to the doctor to confirm that I wasn't dying of a brain tumor, but I found out the problem was my 'diet.' Basically I was eating 800 calories (or less) everyday. I had no idea it was that low and after consulting with a nutritionist I upped my calories to 1600-1800. When I upped my calories I immediately gained 10 lbs (literally within 3 days) and my weight loss stalled at that higher weight for a few weeks while my body adjusted and my metabolism revived itself. After that I started losing again. I lost 100 lbs in about 8 months eating around 1600 calories/day (and that's with minimal exercise). Since December (when I started weighing myself regularly) my weight loss has averaged a little more than 2 lbs/week and I'm eating anywhere from 1200-1800/day depending on my activity level.
While an ultra-low calorie diet may seem like a great quick fix now, the extra few pounds you might lose are sooooo not worth the damage to your body. By upping your calories to at least 1200 (I'd suggest closer to 1800) you'll get the same results but without the damaging side effects. It doesn't seem like 400 calories could make that much of a difference, but it does. Save yourself pain later and aim for a slightly higher calorie diet.