I notice with some apps, as I'm updating, I notice a higher resolution icon is displayed with a progress bar. Typically, the icon is darkened while updating and with some apps, this icon that I see is much more clearer. But when the update is finished, it seemingly reverts back to the old, pixelated icon. It could be that when the icon is darkened while an update is in progress that it may seem high-res to me. However, I highly doubt that. Take the free Yellow Pages AT&T app for example. I received an update for it today and while updating I was happy to see that the icon would be updated as well for the Retina Display. As soon as the update finished, it reverted back to the older icon. This isn't a huge priority, but it is annoying. I tried fiddling around with the problem, like deleting the app completely from my iPhone and then installing it again though. My guesses are that the iPhone still has the old icon saved somewhere or maybe the developer just didn't implement the new icon correctly. I haven't had this problem with most other major apps.