My wife has an Android. I have an iPhone. Comparing hers to mine is like comparing Windows 95 to Windows 7. Sure they both do email, messaging, web surfing, have apps, and basically do all the same tasks that most people do day in and day out. One is a pleasure to use. The other is annoying and sometimes frustrating. Using an iPhone makes me smile. And I'm a lifelong Microsoft junkie (I tried rehab several times). Never having been an Apple fanboy (I don't even like Mac OS a little bit), I'm now a total iPhone fanboy. It's elegant, ergonomic, pleasant, and intuitive. Android tries to come close, but it doesn't. Every time I pick up a new Android device I think surely this one will impress me. Nope. It's only impressive if you've never used an iPhone long enough to appreciate it.
I see people switching to iPhone from Android with some frequency, but I've never seen anyone go the other way _and like it_. If Apple can get the price down a bit, they'll "win" for a long time to come. Android has the many handset makers going for it. It'll continue to do well. There are still a ton of people (90+% last I read) that have yet to upgrade to a smartphone. Android might remain more popular. But Hyundai's are more popular than BMW's. Nobody pits them against each other. That would be silly.
I'll add, that I don't like Apple's locked down approach very much, or it's lack of basic features out of the box, like wifi tethering or just plain moving some damn files around without syncing with iTunes. But most people don't care about those things, and those that do are just the type of people to click here, and have their cake and eat it too.