Yes, just like everything in life. You can only be "magical" and "revolutionary" for so long before people get tired of it. You can only be the hottest chick in the club for so long before you get old and become just another face in the crowd. Apple once revolutionized and now will just catch up and follow trends (bigger screen, NFC, unlock touch gestures, etc). They made the industry more software-driven. But apps to people is like candy. Some you pay and some you get for free. And for awhile, you love it. But too much consumption can make you feel sick of it. You just end up getting lost in a cluttered mess. Nokia was one of the most innovative for a time before resting on its laurels and just rehash the same things. All smartphones are starting to look alike now (slate/slab form factors) and can do pretty much the same things. iPhone isn't "special" anymore. It is like going to Las Vegas. Some people can't afford The Wynn or The Bellagio all the time. But Mandalay Bay or The Venetian are cheaper and just as nice. Three years ago, iOS was well ahead of Samsung's TouchWiz, LG's S-Class, or WinMo 6.5. With a more mature Android, WP7, webOS, and QNX, the gap has closed. If you aren't an app whore, the other OSes can keep you more content.
The Verizon's poor iPhone 4 sales has more to do with reaching a saturation point and the fact iPhone 5 is around the corner. Not to mention LTE and Apple now putting GSM/CDMA radios. iPhone will go completely global and LTE-ready by next year. The iPhone fans who thought about high sales on Verizon were completely overestimating Apple's appeal and underestimating other manufacturers. Android has already been on V for almost two years. Consumers are already used to 4 inch screens, multiple form factors, widgets, etc. They are not going to switch overnight.
The next iPhone needs a new look with iOS or be in multiple form factors. Even then, I think people will grow tired of it. The oohs and aahs are just temporarily before companies find another gimmick. Look at FaceTime. A WiFi/iOS-only version of video calling that Apple stopped marketing about and most people rarely use. But I know a 4 inch screen is enough for some people. Welcome to 2009, Apple. Honestly, for people who are getting sick of iOS should just branch out to other platforms these next few years. Then be a true judge for them all. Everybody copies each other once a trend start or just sticks to what works which makes it is harder to differentiate from each other now.