There's only one feature that Android desperately needs, and it's one I doubt that will ever happen.
Google needs to copy iOS's control over app behaviour. The unfortunate fact is, most developers are no where near as good as they think they are (regardless of platform), and there are way too many apps that will obliterate your battery even when they're only running in the background.
This is inexcusable for a mobile operating system that, by definition, runs on devices with limited battery life. It's even worse when you have a phone that doesn't have an easily replaceable battery.
Too bad this will never happen. That's why I gave up on Android and switch to iOS, despite Apple's obsessive control freakery. When all's said and done, I need a device that I can trust to work reliably. If I wanted a device where I *needed* to screw around and poke at it right down to the OS level just to make it work properly, I'd be using Gentoo.