The following was reported in the Financial Times today but the link seems unreliable so I've copied and pasted below:
European mobile operators are stockpiling an innovative miniature Sim card designed for next generation smartphones for use in Apple’s eagerly awaited iPhone 5.
In one of the clearest signals yet of an impending launch, Apple’s European operator partners have begun to place multiple orders with chipmakers for a so-called “nano-Sim”, the only physical piece of the phone that is owned by the telecom networks.
Apple has not confirmed any forthcoming device but this has not dampened the rumours. The iPhone 5 has been linked with a launch in September or October this year, and there has been speculation about features including a bigger screen, a metal backing and the ability to run on 4G, or LTE, mobile data networks.
The tiny Sim cards, which have not yet been seen on the market, were the subject of a fierce battle between Apple and Nokia to control the design earlier this year. Apple’s proposal was given approval by the industry’s standards group, although other devices will be able to use the nano sim, which is much smaller than the existing micro sim used by many cutting edge smartphones.
Operators expect that the iPhone will feature the nano sim in a slimmed down design, according to two sources with knowledge of the situation, and have begun to store millions of the cards in warehouses in anticipation of high demand for Apple’s iPhone. Apple declined to comment.
Operators were caught off guard by the adoption of the micro Sim for the iPhone 4 as well as the original iPad two years ago, with some struggling to meet demand with their own micro-Sims in the first weeks of sale.
One informed person said that the major networks were keen to be ahead of demand this time, however. He added that the iPhone 5 was likely to be similar sized as the iPhone 4 although slimmer and with a fully metal body.
The nano-Sim, which is 40 per cent smaller than the micro-Sim, is expected to be adopted by other phonemakers over time as it allows for smaller handsets, although it is not expected to be used by Nokia this autumn in its latest Lumia handset that will run Microsoft’s revamped Windows 8 operating system.
Apple has also been in negotiations with some operators about the commercial terms of its sales agreements, which can cover areas such as the number of units ordered and sold. These talks are said to include the forthcoming launch of its phone, although typically span several years.
The use of the micro-Sim caused some controversy in the iPhone, given fears that this was a move by Apple to take greater control over the market, and these flared up again earlier this year when Nokia and Apple went to war over their rival designs for the nano sim.