I'm dying to buy a computer for school. I leave on the 17th and I need to have it before then. Let's say for some reason, I bought my 12" PB today at a brick and morter. It looks like online store is pushing back the estimated ship dates. If an updated one comes out next Tuesday, would they let me trade my powerbook in for a new one? Also I want to gather a consensus on whether I should wait until next Tuesday. If it did come out on Tuesday, I'd have to wait a couple days until they arrived in stores!