Perhaps something for en.wp to emulate: de.wikipedia has recently started a new type of writing contest where two contestants challenge each other to write the equivalent of a "good article" in de.wp:
http://de.wikipedia.org/wiki/Benutzer:Achim_Raschka/Spielkiste
A more or less random user is selected to choose a topic to write about (can be anything). The contestants then can choose a specific article they want to start / bring to "good article" quality. Whoever's article is declared to be of the necessary quality first through the usual community review process, wins the duel. There is a ranking of the "players" who have won the most competitions.
The game was started in June and seems to be quite popular already.