Drinking juice is not the same as eating fruit. Juice is concentrated sugar, devoid of the fiber in fruit that helps your body control it's insulin response. When you consume sugar without fiber your insulin spikes quickly and basically that's a bad thing. Personally I believe in moderation, so rather than avoiding juice altogether I mix it half-and-half with water or seltzer.
I think the V8 veggie/juice blends might be a better choice than just fruit juice since they have fiber, but I'd keep serving sizes small. However, BE VERY CAREFUL about anything marked "light" because it likely contains aspartame or other artificial sweeteners which are NOT o.k. during pregnancy (or any other time in my opinion).
To help with morning sickness, I like to keep a gallon jar full of water in the fridge with sliced lemons in it. It's better than just water with lemon juice because there's something about the oil in lemon peels that is really settling for the stomach. (I only use organic lemons for this since I'm keeping the peels on.) Seltzer with a little grapefruit juice is also great for the tummy.