Comment Re:Can anyone explain in actual meaningful terms? (Score 2) 143
Yes, at least partially. I think the most important component is that you'll only get application resources (like graphics, but potentially others depending on the application) that are required for the device you have. This means you'll not get graphics that aren't even targeted for your device, which is easy and a good thing, because you'll not have resources for retina screens on non-retina devices or vice versa. It basically rips out stuff you'll never need on your specific target device. And as far as I understand it this is not Apple doing magic, but the app developer defining in XCode which resources are targeted at which type of device.
DIsclaimer: I'm not a mobile app developer, I just watched the presentation and demo showing the XCode screens for defining this