I won't repeat what's already been said, but another reason that iOS could be perceived to be dying is that it hasn't really had a major revamp since it came out; we're still on the same old Springboard.
Meanwhile recent releases of Android user interfaces such as HTC Sense look very nice by comparison, it almost tempts me!
We've had the App Store released (OS 2.0), new APIs for devs (OS 3.0) and multitasking (4.0) but the OS still looks more or less the same. But, Apple have, since OS 1.0, had to implement the App Store, develop iPad OS, and implement their version of multitasking, which is no small feat.
With all that done, I expect iOS 5 to feature a new version of the Springboard for everything bar the 3GS that will allow the iPhone to compete on the home screen front with Android. Notifications and the lock screen are also perceived to be in dire need of tlc and these should be upgraded also.
That should silence any critics who suggest that iOS is falling behind.
On a related note, with Google now having to pour resources into their tablet OS, one wonders whether Android development for the phone will slow down whilst they take the time to bring out the unified version (3.1), much as happened over the course of iOS 3.x and early 4.x.