Armin Vit has a smart take on the Instagram icon redesign (via John Gruber):

Unlike Uber, that replaced it’s “U” for a metaphysical atom, the change here is only aesthetic. It’s still a camera. Yes, at first it will be hard to recognize it, but when you have 200 million people tapping on it everyday, multiple times a day, that’s the kind of brand engagement that Coca-Cola or Nike would kill for. When it comes to “brand impressions” and “brand touchpoints”, Instagram (and Facebook and Twitter and, yes, even Uber) have no shortage of opportunities so it will only be a matter of time — three months, probably — before this is known, recognized, and considered as the Instagram app icon. Simply by repetition and usage. Hell, I was starting to get used to the Uber icon until they pulled out of Austin this Monday.

If people ever stop checking Instagram obsessively, I don’t think it’ll be because of an icon change.