iOS 4.2 took a little longer than planned to roll out; a last minute WiFi bug in the 4.2 golden master caused a delay of a few weeks to rev up to the 4.2.1 version that was released on Monday. Despite this, Apple is rumored to have iOS 4.3 already waiting in the wings for a mid-December release. That update is said to bring a new subscription billing API for in-app purchasing, according to MacStories, enabling app developers to collect recurring charges directly through iTunes for print, video, or other content.

In particular, these new APIs are said to be behind an upcoming subscription news app from News Corp. CEO Rupert Murdoch recently told Fox Business that the app, called The Daily, would launch on the iPad and other tablets around the beginning of 2011, and would cost readers 99¢ per week for daily news updates.

Daring Fireball later reported that News Corp had been working closely with Apple on the necessary functionality to enable subscription billing and possibly push updates of new content to the app. Sources pointed to an early-December press event to unveil the new capabilities, and MacStories reported that an iOS 4.3 update was slated to come out the following week.

MacStories also speculated that iOS 4.3 would include some bug fixes and other maintenance code, including improved support for AirPlay from first party iOS apps. Apple is rumored to be sticking to its mid-December release window, but if that deadline blows by, the holidays will add at least a few extra weeks to the wait.

Adding direct subscription billing APIs could provide an easier and more consumer-friendly revenue stream for services like Hulu Plus or magazine publishers. Still, it won't address the concerns that some content providers have that they won't be able to collect valuable demographic data or use their own payment systems. A 70 percent cut via iTunes is still better than losing subscribers altogether, though, as more readers ditch traditional print sources for online content. Murdoch and News Corp. seem poised to prove that the model can work for a modern newsroom.