Interesting observation. If there is any truth to it, it could be because good games take longer to develop, or it could be because it may take a couple of years for gaming companies to start realizing "Our sales aren't getting any better since we're letting too much shit slip through the cracks. Time to once again give fans what they actually want"
Next gaming phase could be party games, even though I cringe at the thought. I think the Wii U might make them more popular if they do a better job of them than the Wii did. Large amounts of people can be attracted to games that aren't 100% photo-realistic and filled with blood and violence, provided they are fun enough. Just look at Angry Birds for instance. Such a simple game concept and graphic-wise, yet you can't turn around in a store without seeing hot-selling Angry Birds crap I think maybe some people might start getting bored of these hyper-realistic shooters and racers and may start favouring things that look and feel unique. That is something I would look forward to, a little more colour and diversity in the top-charters
Overall, I see that things may shift towards more Linux/Unix in the near future, if Windows continues to be so incredibly closed about who gets to use the store; having cashed in way too late once again. Nintendo has made a mistake of being the first to move once again, and the tablet is doing little to innovate or win favors.