WebKit port mantainer Ryan Leavengood, posted about his ongoing progress both on the Haiku site and the Haikuware site, detailing what he's been up to, progress made and halting problems. One problem (or maybe not) is the fact that the compiler WebKit uses is GCC 4, while BeOS and Haiku use 2.95.3, a much older version. He discusses not only what issues this brings to the table, but also how to overcome it.
Head over and read both posts, they make an interesting read. Good luck and good progress with the port Ryan, we're all looking forward to the final (and successfull) result.