Based on the sales numbers from previous Quarter it appears that iphone is losing its momentum. Over the last few years, there hasn't been a new innovation in terms of phones. When iPhone burst into fame, it was the multi touch UI and Appstore. But over the last few years almost every phone has all these features and competition is only on the Speed and Megapixels etc.
android market has also matured well and several low end Android offering does what iphone does reasonably well. And In high end space samsung is churning out several exciting offerings which have for past year bettered iPhone in all departments.
Going by apple's release cycle for iPhones, we should expect an iPhone 5S shortly, and with a 5S Apple will try to match the same form and look and feel. But considering that iphone 5 didnt evoke excitement in the smartphone market, will 5S make any ?
But if Apple still believes in maintaining a tight schedule, most likely in 2 years time, Samsung will overtake Apple even in its home turf in us.