According to Techcrunch, Foxcon, who manufacturers the iPhone for Apple, will have pushed its production to 800,000 units a week. It is very near to maximum capacity. To go any further will require converting other production lines, which is quite complex.
If this speed is maintained, they will surpass 40 million unites per year.
But production could be boosted in another manner, rumour is that Apple will offer an iPhone nano for the end of the year holidays.
[translation by jwa]