This is a big win for Yahoo. I think they're realizing developers are their best chance to stay in the game, so they're opening up anything and everything in an attempt to hold on.

Definitely a smart move.

I'm mostly interested in YQL (Yahoo! Query Language): http://developer.yahoo.com/yql/docs/.

I find it surprising they didn't go with an existing technology for querying (ala SPARQL: http://www.w3.org/TR/rdf-sparql-query/).

That being said there's lots of stuff developers can build leveraging this information. I've had a lot of fun experimenting with BOSS (http://developer.yahoo.com/search/boss/).

I think this is on the same page and is definitely a step in the right direction for Yahoo.