After some really fantastic help & support from potyl I got Gtk3::WebKit to pass it's installation tests on Ubuntu 12.04 (precise, LTS).

Given that this requires one step that cpan/cpanm won't deal with out of the box, in the interests of documenting for the interwebs ...

Dependencies ... at least on Ubuntu 12.04:

aptitude install xvfb libgirepository1.0-dev pkg-config libgtk-3-dev libglib2.0-dev libglib2.0-0 gir1.2-webkit-3.0
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