What about the huge shift in software itself? In this generation, most titles move closer and closer to "blockbusters". Most of them implement popular aspects of different genres to appeal.
Most games nowadays contain shooting or RPG elements to appeal to the broader audience, the "hardcore". The "core" gamers on the contrary seem to flee the industry as there's nothing to interest them after gaming for 20 years or just growing old.
On the other hand, huge wave of "casuals" has entered the market with the Wii, them only interested in really mainstream IPs (like Mario, CoD, Sonic) or just casual titles, like Wii Fit, WSR and EA Sports Active.
In my opinion, the shift in software and consumer tastes has been very significant this gen. Casuals on one hand (through the Wii), and hardcore through the other (via HD) have squeezed the core gaming population out of the equation.
My themeforest portfolio:
