To combat this, Amazon is limiting PS3 Slim sales to a single unit per household - a common stance for hot new launches. For the majority of users, that won't be a problem - after all, who needs more than one PS3? However, those trying to snatch them up for gifts may find themselves getting the shaft temporarily. Amazon's actions should help prevent people from buying them in bulk and reselling them on eBay.
Many people seem to be questioning the source of this apparent shortage. If it is artificial, maybe Amazon is working to prevent a real shortage? Perhaps Sony underestimated the potential demand for their reworked PS3?