Examples of and brief treatments upon transmedial stories which focus on what Wecks calls "world building." The key aspect of world building, transmedial projects seems to be continuity of world. IE, the Star Wars franchise's gargantuan canon, comprised of books, comics, videos, videogames, LARPing...that is an example of transmedial world building.
But Star Wars transmedia is mostly unconscious, in that the medias do not communicate in real time with each other and discontinuities/contradictions in canon proliferate. KOTOR is less an extension of the SW books universe than it is a parallel universe.
But these projects heft transmedia consciously. Though different media may access different characters in different storylines, those storylines are all connected to make up one comprehensive world. As in the example of Defiance, a new show AND new MMORPG coming out of Syfy next year, what happens in the game will effect the show, and vice versa (even though characters will not be shared between the two).
Of the examples, Defiance seems to be the most ambitious both financially and administratively. It's exciting to see money thrown at new things, sure. However:
It is easy to be excited about concept; we'll see what the execution looks like.