I would say vacuuming is more productive than blasting it in further. On something enclosed like a PS3 anyway, use the hose and a plastic extension to just lightly suck away over the vents.
On the real note of the thread, if it is excessive noise then you probably should be vaguely concerned as I have never found my PS3 loud at all, even when loading, (i.e. no TV sound), I can barely hear it, just a faint whir in the corner, I have the 40GB European model, what model is yours?
Charlie -