We had WebKit 2 rendering things to screen in a past GSoC project, there is no reason we couldn’t do it again. I just hope this time the code will be a bit cleaner and can be merged into the main development branch of WebKit.
While the WebKit codebase is very large, there are not so many parts involved in making a port, and, once you have identified them, it’s actually a rather linear process (fix one bug, hit the next one, fix that, and so on).
Anyway, even if it doesn’t end up with a fully working browser, a lot of progress will be made. That is still a good GSoC project, and maybe Zardshard will continue working on it after GSoC is over, too.
I hope @Zardshard is not feeling completely lost in WebKit sourcecode at the moment 