Only a couple of years ago, a deal like this would have been unthinkable for either party --- the legacy media wouldn't have deigned to open themselves to the hyperlocal parties, and those parties would have found it suffocating to play with the Goliaths.
Mutual interests have emerged: legacy media want the granular coverage, hyperlocal media need the larger impact to generate a better business model.
The nature of the deal is lacking in financial specifics. It's all about exploring advertising opportunities, collaborating on content, exchanging links and audiences, and agreeing to examine the common opportunities.
But it's an interesting model for others to study. Seattle is one of the strongest examples of a market able to pursue such a deal, but there are others near and far.