Game consoles shouldn't -really- be getting too dusty in the first place. Also, 7th Generation game consoles require much greater care in terms of cooling. You can't just stick your Blu-Ray player under it and your set top box on top of it with millions of cables blocking the fans. You must make sure there is at least 10cm of free space at the back of the unit and about 5 on each side.
Also, I do NOT recommend that you stand it up, this is when people are getting the scratched discs. Apparently it's because the laser diode assembly is actually touching the disc. This is a BIG design flaw as the diode slides up and down on two rails. Plus, if it didn't scratch the discs, it would probably not read them because it would have an extremely hard time trying to focus (this is especially true for dual layer discs). This is why you should never touch the lens because it can force them out of focus and possibly scratch them.
But, if you are absolutely sure it's a dust problem, do NOT use canned air, this will blow the dust around the system and probably cause even more problems. Use a high powered vacuum cleaner instead, but be careful as vacuum cleaners do like to generate a lot of static.
But again, do not use compressed air. The dust might get disturbed, but if it's not coming out (which it won't), it will settle elsewhere and cause more problems.