No sugar, however good, is going to be beneficial to a high-protein regiment. I'm pre-med, and can tell you that this is not a good substitution if your goal is to build muscle mass.
Jamba Juice is tasty, but that taste comes at a price. In a protein shake your caloric intake comes almost solely from protein, (which builds muscle mass) and in a fruit smoothie it comes almost exclusively from carbs (which stores fat and potential energy). Your body will build fat far easier than it will build muscle, so if you are serious about getting in shape, you need to limit your carbs as well as increase your protein. Otherwise they will cancel eachother out- the protein you eat will be wasted just burning off these extra carbs you took in. Some are fine, but jamba juice is far too excessive. For a high-intake diet you'll want the carbs to be a small fraction of the ingredients in your shake, NOT the main one!
Where fruit is concerned, just because the sugar comes from a better source doesn't make it good for you in excess. Not on a high-protein regiment like South Beach or p90x for instance. **It's STILL sugar** Your body still absorbs the sugar and converts it to fat stores, complex or not. One is obviously better, but it doesn't make it good for your goals in any way. Don't cut fruit out entirely. Just know that it is not beneficial to body-building, (aside from the vitamins you get in your normal daily servings) and is not what you're looking for in terms of protein intake.
If you're trying to build muscle mass, you need to stick to a true protein shake, not a protein-infused high calorie high carb treat. Jamba juice is still considered a junk food, even if they pride themselves on being the best, most-nutritious junk food around. All four protein shots give you about 40 grams, which is the same amount as just one scoop of protein powder. And the scoop doesn't fill you full of carbs and wasted calories. So put it in a ziploc, and take a waterbottle to work. Then mix the two before your workout, and even if it doesn't taste as good, it is much more cost-effective and will achieve better faster results. Compare the two on nutritionData or a similar site if you are still unconvinced.