updated 12:12 pm EDT, Mon July 29, 2013
Beta 4 said to be going live later today
Apple is planning to release just three more betas of iOS 7 before the gold master version debuts in early September, a BGR source claims. Several sources suggest that beta 4 will go live later today, now that the Developer Center has been fully restored. The code is expected to contain bugfixes, graphical and UI enhancements, and "a couple of other updates," according to BGR.
If the suggested GM timing is correct, iOS 7 and/or new iPhones could ship in mid-to-late September. A gold master is essentially the finished version of a piece of software, issued to developers and/or manufacturers shortly before a product hits stores. To date, Apple has only confirmed that iOS 7 will reach the public sometime this fall.