It is not unusual that some systems get so dusty, it is always probably that when a construction site is near your house that it gets like this.
I have seen many PC's that look like this on the inside, and that's just normal: electronic components just tend to attract dust. Look at your TV or between the keys on your keyboard.
It is in the end just lame that Sony announces a product that has a 'lifespan of 10 years' that just can't whitstand some dust. If it is a lot of dust or just a bit dust, thats something you can argue about. But electronic devices shoudn't malfunction because of it, certainly not products that should be state-of-the-art.