Slightly ahead of the keynote later today, Apple has pushed some of its new APIs for developers into the open-source channels. The class in question is a new view that appears to replace the current iOS and OS X WebKit implementations, which enables apps to show webpages and other content inline.
The new framework seems to indicate a focus on cross-platform API compatibility, between iOS and OS X. The leaked framework seems to be fully feature-compatible across platforms. This differs to the situation today, where developers must use the ‘WebView’ class for OS X and ‘UIWebView’ for iOS. This should help developers write more reusable code.