People don't like to wait. In a world where Amazon gets orders to a person the next day, a checkout flow that doesn't set extremely clear expectations for the timing of order processing, fulfillment, and shipping will make people angry. Google forced consumers to work particularly hard to find this information. Here's the confirmation email I received: http://i.imgur.com/CbMSu.png
I'd argue that the design of this email is particularly poor, in that the ONLY thing I care about at this point is: when will the thing I bought arrive at my house. Every single piece of information other than: what was purchased, when it will arrive, and the delivery address should be moved much lower in the information hierarchy.
Embarrassingly enough, I sent Google customer support frustrated complaint that I hadn't received a notice about an expected ship date, only to have them (rather mechanically) direct me back to this original email.
Apple still does a great job at this experience. When a brand new iPhone is taking a couple weeks to arrive, the folks I've witnessed are usually not angry - they're excited.