General Impressions:
Motivation can be a problem with traditional learning and with educational games. Non-engagement can cause a lower participation level. With educational games, non-gamers are often not as motivated to play, and don't get as much out of it.
Hidi and Renninger's article presents a 'Four-Phase Model of Interest Development' where interest is broken down into four phases of increasing interest / motivation. The earlier stages are typically externally generated, while the later phases are typically internally generated in the mind (curiousity, questions proposed). With respect to gaming, how could we generate initial motivation / interest?
I think that gaming itself might be enough motivation to generate a starting interest in many students, and it will be up to the game (design) to further that interest. Gaming itself favors learner / player-centered learning, so this will help game players generate goals and progress through the game (and up the ladder of interest development).
One question that I can't answer is how to deal with those who don't have much of an interest in gaming. Hidi and Renninger note that initial interest development doesn't happen in isolation- which suggests that a good teacher might be able to spark their mind and get them interested. On the other hand- it may be difficult to get those with a predisposition against gaming to 'break down' and give it a try- the author says that personal experience, temperament and genetics come into play with individual interests. The answer may lie in scaffolding and personality (different types of learners) - providing multiple forms of instruction may be the best way to go.
Hidi, S. and Renninger, K. (2006). The Four-Phase Model of Interest Development. Educational Psychologist Vol. 42 (2), To be published Spring 2007.