Look to see a big bump in sales in Sept when all the fall games start to come out and when the new PS3 price drop has effect.
As well the sales could still be year over year worse than last Sept and it wouldn't be the end of the world. The games industry traditionally follows a console cycle (though that will likely be broken up this time around with the launch of Natal and Sony's Waggle next year) and so once you're past the peak some years after a launch, your sales will necessarily decline until the next console launch.
I think NPD only tracks retail sales though, so any money diverted to downloadable content, Steam, or iPhone games would seem to "disappear" from their charts.
Largely everything seems to be following the same set plan.
Next year might be an upset year of this traditional cycle though, since Microsoft and Sony are releasing hardware upgrades in the form of their motion controllers. Microsoft has been quoted as saying that the launch of their Natal upgrade would be akin to a console launch event.
This is from my experience in the games industry: big games prop up the big sales figures. The majority (over 70% IIRC) of sales are made after a game drops below half of its original sale price. Add the two together for long enough and you get this sort of major sales slide.
Avid gamers, think back to 2008 and 2007... I spent way too much time in front of my TV back then, because there were quality titles coming out.
In 2009 I did not buy a single game until Batman: Arkham Asylum this month. This is the first time in ever that I can remember not buying any games for the first 8 months of the year.
And the worst part is, this will get worse. Many of the most anticipated games of the holiday season have gotten pushed into Q1 2010. Q4 2009 is going to go down in history as a very, very painful quarter for game publishers.
Many of the big titles that were due this year have been put back to a 2010 release. This Christmas we have only have three big-hitters: Assassin's Creed 2, Uncharted 2 and Modern Warfare 2. Good for publishers of those three I guess. We also have the recent releases of the PS3 Slim and Rock Band: The Beatles.
Next year we get all the games that were delayed this year (Mass Effect 2, Bioshock 2, Splinter Cell: Conviction etc.) on top of a number of good releases that were originally due. I predict that 2010 will be an on year.
