It's a no-brainer that the next trilogy of films will continue the proud tradition of featuring planets (and moons) entirely defined by a single, highly visual characteristic. From the original trilogy alone, there's the desert planet of Tatooine, the jungle moon of Yavin IV, the ice planet of Hoth, the cloud-covered world of Bespin, and the forest moon of Endor. The distinctive environments of these locations allow the settings to be easily remembered and understood by the audience. The worlds even have identifying colour schemes: Tatooine is predominantly yellow, Hoth is white, Endor is green, and so on. These single-feature locations provide the movie makers with an effective shorthand for explaining the settings to the audience without getting bogged down in endless exposition. From the trailer, it looks like Episode VII includes a water world, assuming the watery setting isn't just an ocean or a lake. Since it wasn't raining in that brief segment of the trailer, this new planet of course feels and looks completely different to the other soggy planet we've seen, Kamino from Episode II: Attack of the Clones, helping to maintain the healthy streak of clearly distinct worlds. (Kamino was primarily portrayed as a world of storms rather than just ocean.) Including a more typical water world in the Star Wars films is a good move since it, once again, provides the audience with a setting that can be understood at a glance. As an aside, on seeing that sequence with X-Wings zooming across the surface of the water, readers of the original Marvel Star Wars comics must have been reminded of the water world Drexel (where Luke Skywalker and the droids were stranded in issues 11 and 12, published in 1978). Which is a far better association than, say, the Kevin Costner film, Waterworld.