I think anyone with half a business sense will tell you that creating a false shortage does absolutely nothing for you. Sony got a shitload of hype to begin with and I highly doubt an artificial shortage would have helped them at all. They're trying to push Blu-Ray remember?
That's like telling a fledgling business to tell their customers that they're so busy, that everybody has to wait a mandatory 45 minutes before they get serviced. People aren't going to wait there and keep asking themselves what the fuss is all about, they're just going to plain leave.
"Nagi, how do you feel about being 'normal'? Normal means that if you leave something alone, it just remains that way forever. So if you can't stand that, then you have to be "not normal" in some area... - Seiichi Kirima's dying words