If you ask Brian Chan, senior designer for Boston-based Rock Band creator Harmonix, what the most significant development of this current generation of consoles is, his answer is easy, if also multi-faceted: motion controls, achievements, and microtransactions.

"I'd weigh them pretty equally," he told Gamasutra. "They've clearly had the widest impact on the trajectory of games through the present and into the immediate future. Motion and touch captured new audiences and established wholly new game experiences."

It's not an irrelevant point. The music/rhythm genre, in retrospect, has been at the forefront of the entire gaming industry: guitar peripherals foreshadowed motion devices; downloadable songs presaged the explosion of DLC add-ons; and even the Rock Band Network seems to at least partially be the prototype for Activision's Call of Duty Elite service. Is this a trend that will continue onwards into the next generation?

"Yes," Chan says, "and I think it's largely because the genre is based on a medium that is several orders of magnitude more mature. Music is a ubiquitous and inextricable part of people's lives -- in addition to being a powerful medium in isolation, it tends to go with everything else. With social media and the democratization of music software, more people are making music than ever before.

"So, if, indeed, the future is casual, trans-media, and highly monetized, then popular music, as an expressive medium and a media format, seems about as flexible and future-forward as any genre or fantasy I can think of."

In line with that, Harmonix has been shifting its focus, while continuing with the popular Dance Central series for Kinect, recently releasing Vidrhythm for iOS, a video-sample music creation iPhone/iPad app.

There are, of course, many an industry pundit and game enthusiast alike who has written off the Guitar Hero/Rock Band craze as a fad, replete with catchy-but-ultimately-futile gimmicks such as plastic guitars (usually grouped alongside motion controls and Facebook/mobile titles).

"Gimmicks, so-called, are really just risky moves taken in the larger narrative of innovation," Chan responds. "They are bold and sometimes stupid, but we should applaud such risk-taking. And sometimes they are thin at the start, but many good ideas mature over time and with iteration."

And in regards to motion, 3D, and plastic guitar peripherals, he says "these just seem like pretty obvious steps in a larger project of immersion, of forgetting yourself in an experience." Indeed, the music genre as embodied by Rock Band is, in many ways (both good and bad), the epitome of immersive gameplay. But how much does this help -- and hurt -- the franchise's lifespan?

"Immersion is a difficult thing to grow across successive games because of the tendency towards increasingly deeper immersion, which is often similar to a move towards the hardcore. Maintaining accessibility for the newcomer while deepening the experience for the veteran is incredibly tough, and it only gets more difficult as a franchise develops."

This has the tendency, Chan told Gamasutra, to keep the series treading water. "What is typically needed in this situation is a pretty dramatic break from the norm. Rock Band and Guitar Hero both attempted disruptive moves in their last iterations, to mixed success commercially. Still, I'm convinced that the only way to move ahead is to take risks in order to offer new experiences, so I'm glad both parties tried their best."

One of the key elements in this effort will continue to be casual players, Chan believes, given the huge overlap between individuals who are interested in music and those who don't play games. "Casual has been the trajectory of the years since the DS, and I think that will continue to encroach upon our notion of 'mainstream games' - i.e., the ones that make the lion's share of the money."

Just how the console manufacturers approach this still-burgeoning market will be a major influence on the shape of the next generation. He specifically cites the breakout success of Minecraft, a game which speaks to non-mainstream but nonetheless quite hardcore tastes.

"It's wonderful that the technical and commerce infrastructures have matured such that these sorts of success stories can come about in a quality-based way, without the aid of publishers or huge marketing budgets.

"That said, I hope that first-parties and publishers continue to serve a sort of patron or curator role with respect to creatively-adventurous games; personally, I have always gotten a lot from the numerous fringe releases and 'art games' that Sony has supported on their platforms since the days of the original PlayStation. I hope that the market evolves to support content from all points along the indie-to-mainstream spectrum."

That's an interesting point, coming from a company that has itself run the gamut from indie to mainstream, from independent studio to, essentially, corporate subsidy. Is there still room for both sides of the development coin, particularly in the industry of tomorrow?

"It's clear that times are tough for larger independent studios -- save the obvious anomalies like Valve, who has evolved into a platform owner. Tiny games and huge games seem to dominate the conversation now, and, likewise, we've propped up infrastructures that seem optimized to service specific form factors, particularly the 99-cent app and the triple-A game."

"While online marketplaces allow for many form factors to exist, including many in the mid-range, we seem to consolidate around a few key pairings of price point/product scope."

"I'm hoping that innovative indies continue to break down barriers here," he continues, "as Riot did with League of Legends. Not dissimilarly, Harmonix was an early pioneer of the 'game-as-platform' concept and continues to set the bar for volume and consistency with respect to our DLC business. I think that we've learned important lessons from that experience that we will bring to bear in our future products."