If you're looking to purchase the latest and greatest iPhone when it is released by Apple, rumored to be announced September 12, you might have even more difficulty than usual. Sources close to Sharp's production of the screen for the device have said Sharp is experiencing issues with the screen which has delayed the start of mass production.
If Apple is unable to obtain enough supply for the next-gen iPhone, it will place restraints on how many can be produced and sold, limiting availability and sales numbers. Sharp was supposed to begin shipping the screen at the end of August, but has been unable to start mass-producing due to the technical issues.
It is unknown when Sharp will be able to begin shipping the screens. Remember, the screens then have to be installed in the device, so there is still lead time, even after the screens have started shipping. If you want the next iPhone, I suggest you wait in line, or it could be awhile before supply picks up.