iPhone 7 sales expected to be lower this year...

As the likely launch date of the new iPhone approaches, Wall Street is getting jumpy about its chances of driving up Apple's revenues and profits. The next-generation device, which may be called either the iPhone 6S or iPhone 7, is expected to launch in mid-September, and Apple's shareholders will expect it to build on the huge success of its predecessor.

The company is widely expected to unveil the new iPhone on 9 September, and new reports today suggest that the device will go on sale in key markets, including the UK, on 18 September (see below).

Those dates would be in line with the usual launch schedule for the iPhone: last year's upgrade was revealed on 9 September and made available to buy on 19 September.

Unlike last year's all-new device, the iPhone 6S or iPhone 7 is likely to include only incremental improvements over its predecessor – and that could lead to disappointment for Apple's customers and shareholders.