Examples
Epiphany
Epiphany or GNOME Web is the reference application using WebKitGTK so it has been ported to WebKit2 API. We can find the metabug with all the patches here.
Yelp
Yelp is been ported to WebKit2 API and you can find the bug with the changes that were made here.
Evolution
Evolution is been ported to WebKit too. You can find the branch were the changes are being made here.