Gamasutra has a whopping 31-page article exploring the waning popularity of the platform genre in recent years. From the article: "Platform games used to enjoy a 15% share of the market in 1998 - and considerably more in the 16-bit era - but 2002 Chart Track results showed a staggering drop to 2%. As consequence, marketing circles are reportedly deliberating that platform games – as a genre - are not as attractive to consumers as they once were."
The author blames forgotten "effective design principles of [the] past" rather than a lack of consumer interest as the culprit. But could the recent top-selling New Super Mario Bros. for the DS in both Japan and the US signify a resurgence of the platformer, or is the portable scene a different genre beast altogether?