The question that comes to mind, though, is whether we are actually talking about one or two distinct audiences here. Ian classifies casual games (and consequently, casual gamers) as follows:
Casual games typically offer short gameplay sessions, come at a lower cost than hardcore games, and allow play on more ordinary devices like personal computers and mobile phones.
So, is there a difference between the "internet" casual gamer as identified by people who play Solitaire and Bejeweled, and the "console" casual gamer that Nintendo is pursuing?
Let's, for discussion's sake, assume they are different markets and see what is the same and what distinguishes them. I believe the overall impulse is the same for both audiences. Ian quotes a white paper from IDGA that characterizes casual gamers as "gamers who play games for enjoyment and relaxation." (What I had described as recreational gamers.)
He also presents a very useful matrix for understanding the motivation behind casual games; examining time, money and control and the casual gamers assumptions (or limits) for each in terms of complexity and investment. He argues that "casual" is a misleading term because it implies a limit on the investment the player will make; but the common business model (try then buy) is based on users willing to invest time beyond a simple demo or mini game.
He suggests that "informal" is a better adjective than "casual" and that informal allows for variants, such as indifferent, spontaneous, or fleeting. But that they can be repetitive (allowing for more investment of time, and therefore a viable market).
Bogost explains this much better than I can so I encourage anyone interested to read his essay. He also goes into more detail concerning "fleeting" games and their application to the news game genre (an area of particular focus for him). What I want to explore here is the implications for the console market.
Ian explains why "respecting" a casual gamer's time commitment should not necessarily mean short. (And, by extension, why providing only minigames is an unnecessarily limited strategy for game developers.) It may be better to say that the time commitment is variable rather than short. I may choose to play for five minutes today, but for an hour tomorrow. Again, this applies to informal gaming on both the internet and consoles.
The two areas of Bogost's matrix that do cause trouble for the nouveau console gamer are money and control. According to the matrix, informal gamers want games that are easily accessible, low cost, and/or run on existing equipment (such as a PC). This is definitely not true of the market Nintendo is pursuing.
Although the Wii is the cheapest of the current generation consoles, $249 + $50 per game is not cheap by any measure. It is a considerable investment for informal gaming. The innovative controller might explain part of the allure (claims that it is a "fad"). But certainly not to the level of sales the Wii has experienced for practically a full year since its release.
The difference in commitment (and in audiences) might be compared to the difference between someone at a dinner party suggesting a game of cards versus someone bringing a board game with them. Most people have playing cards, you can decide on the spur of the moment. But owning and bringing a board game shows serious intent to have fun.
Another difference, which I mentioned previously, is scope. Internet informal gamers tend to play games to pass the time: Solitaire, Bejeweled, puzzles... individual games. Informal console gamers would prefer to play as a group. Even if the game itself is single player, they will play together -- encouraging, advising, kibitzing, and even playfully joshing whoever has the controller.
This expectation that they will be able to enjoy the gaming together may be part of what helps the console informal gamer overcome any resistance to the initial steep investment. And it is certainly an aspect Nintendo emphasizes in almost all of it's marketing. One aspect of this theory -- if it is correct -- is that there needs to be steady flow of innovative games if this market is to be kept flourishing. Hardcore gamers can sate themselves on multiple releases of similar shoot and kill games, but there are only so many versions of Monopoly or Clue you can play before your friends will get tired.
Ultimately, I think we are talking about two separate audiences. Or at least two ends of a single spectrum: the informal internet gamer and the expanded audience of informal console gamers Nintendo is pursuing. The industry wants to treat them as one at the moment; possibly because they don't understand either! But it will be interesting to see if by sheer volume alone, the two audiences differentiate and force a rethinking of the simplistic hardcore/casual two-way split many companies in the video game industry are pursuing.