Have they EVER waited for rivals to come up with something better than the iphone before they created the next one ?

isn't it more like THEY create something FIRST so they are consistently ahead of the competition. Plus historically, Apple has consistently updated its iphone once every year. iPhone history

Why would Apple care about the iPhone 4 once it releases the iPhone 5 ? the trend for Apple has always been to stop production of the older model and continue revenues from the sales of newer iPhones. (iPhone 4 discontinue production 0 cost, iPhone 5 start production and sales) This way they maintain a constant profit from their iPhone's without the risk of the price ever decreasing due to age. Like for example Nokia or SE or HTC