Could it be that a major shift in App Store policy is underway at Apple? After repeatedly denying entry or pulling applications that duplicate any of the core functionalities of its iPhone handheld, Apple appears to have had a change of heart this week with the appearance of four third-party browsers in its iTunes App Store, each of which are now available for download.

These new applications include Edge Browser (free), Incognito ($1.99), WebMate: Tabbed Browser ($0.99) and Shaking Web ($1.99). But there's a catch. All of these browsers are based on Safari’s version of WebKit, which is built into the iPhone SDK, and merely enhance the functionality of the existing browser. In other words, this doesn’t necessarily mean Apple will open the gates to iPhone versions of completely separate third-party browsers, such as Firefox or Opera.

Regardless, the new apps do mark somewhat of a change in Apple’s position regarding duplication of functionality, and will hopefully represent a step ahead for the iPhone in becoming a more open platform for application developers.