If you think about it, GT5 got 1.8 million people into stores in two days. These are people that most likely wouldn't have been in the stores if it wern't for GT5. Now that there are 2 million more people in the videogame department they will see microsoft games and want to buy kinect etc...
In conclusion, big blockbusters help not only the console it's for but the whole video game industry :)))
For instance let's say 1 out of ever 1,000 GT5 buyers would be interested in Kinect but didnt know Kinect existed
that means Kinect sales could have been boosted by 1,800 in GT5's first two days. Now do this with more games..of course it would help ps3 a lot more but you get what I'm saying. Same applies to wii.
It makes perfect sense...duh