I love this post from Andreas Voniatis of Artios. Artios have created an intent API which looks at content in the SERPS and on-site to determine which keywords share the same search intent.
I didn't attend the Pint-Sized Marketing meetup, but clearly I've looked over most of the slides (because I'm a nerd). I particularly enjoyed Matthew Kay's slides on their in-depth content briefing process at Aira. Brilliant!