Us nerds care about obscure nifty features, but 99% of people don't.

In fact, I think in some ways iOS 4 is a step backwards, in that it adds half baked "features" like folders and the multitasking UI (my gripe is with the UI only). They aren't nearly as well thought out as the rest of the OS.

Android does have some well implemented features which I like though, specifically Facebook integration with the address book, etc.