It is a good question to ask ... and not just about WebKit, but our involvement in other web browser ports, such as Mozilla, to embedded systems.
As a company Crank focuses on customers who are building embedded products. In addition to our professional services we also have a complete embedded user interface development and runtime product: Crank Storyboard Suite ... sign up now for the upcoming public beta!
The reality however is that as long as the graphical web browser has been around, people have seen it as a convenient deployment mechanism to create cross platform applications ... with increasing user interface complexity as the browser technology has matured and evolved. Today we can look at the various sophisticated JavaScript and AJAX libraries or pseudo platforms such as Google Chrome to see that the paradigm of the browser as the app isn't going away any time soon.
Many of our customers have existing web based design platforms, often using browser based plugins to provide an API that allows application extension and customization of their products. However, the typical desktop browser is not what an embedded application would deploy.
In the embedded environment 90% of the typical web browser adornments are thrown away. Features such as preferences, bookmarks, printing, toolbars, status bars, extensions, multi-window support and perhaps even dialogs are stripped away leaving only the core technology; layout, rendering and scripting engines.
A custom user interface is crafted around these core technology and provides the visual presentation as a frame into which the browser based functionality can be integrated. This user interface is something that generally defines the consistency, look and feel of the entire application/system/product.
Storyboard enables a rapid creation of this user interface "frame" and through our plugin base design for content rendering integrating a browser engine, such as WebKit, becomes a straight forward activity.
Another way to look at it is as follows:
A similar type of strategy is often used in cell phones and smart devices, but with Java taking the place of the browser to provide the common sand-boxed environment for third party applications to run.
... not that we don't like Java, if you want to run that, Storyboard can integrate with that just fine too =;-)