Higher hardware prices are driving a lot of the intense revenue growth we're seeing. (Software revenue alone was totally stagnant in Japan from 2006 to 2007, for example.)
Higher software prices also contribute. 360 and PS3 have higher prices than last gen, and games like Guitar Hero and Halo 3 are pushing even higher prices (and tons of sales).
On the other hand, dropping prices over the course of the generation can offset increased unit sales, and create the illusion of no growth. And I'm sure people will agree the emergence of games like Brain Age is pretty significant, even if they drive less revenue than a much smaller selling 360 game.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.
