iMore Reports August Launch For iPhone 5S
This falls roughly in line with KGI Securities current model, which was released yesterday. Taking an August launch to be correct and accounting for an average three-month gap between public announcement and Gold Master status of a new iOS version, WWDC appears to be too late to announce iOS 7.
I suppose there is a possibility that Apple could return to the ‘iPhone OS’ release schedule, by announcing iOS 7 at a special event in April or May.