I recently purchased an iMac, and while I initially perceived its screen issues as "tolerable," two days later I was ready to send it in for replacement. I went through the motions, got my RMA and FedEx tag, and dropped it off at a FedEx location on Saturday. The Rep I spoke to on the phone at Apple told me my replacement would be sent out as soon as my return was in transit. It has been 3 days since it would have been "in Transit," and I have yet to receive a shipping confirmation on the replacement unit (my order status says it should have shipped yesterday). Is this normal? Does Apple need to have the defective unit in their possession before the replacement is sent out? I'm short a computer and wondering how quickly this will be resolved. If anyone has any insights or experiences with this, I would love to hear about it.