As someone who travels, there are many times when a simple word-by-word translation of something is incredibly valuable. Hell, as a vegetarian, just knowing (or having a pretty good guess) as to whether a menu item somewhere lists 'seaweed' or 'sea urchin' is worth the price of admission.
Based on the demo, I think you're more likely to get seaweed substituted for sea urchin. In fact, that's why a translation dictionary is useful ... you'll get multiple translations which will allow you to reconstruct the original meaning of the word. I don't see how this can be implemented with this type of software, therefore, I think it's really limited in scope.