Well, rock'n'roll, looks like Yahoo!'s* Search Monkey is going live today. Apparently this will allow us as site owners to (cribbing from RWW's report) "share structured data with Yahoo!, using semantic markup (microformats, RDF), standardized XML feeds, APIs (OpenSearch or other web services), and page extraction. " On the basis of that data, other developers will build apps and users will enhance their search. This seems to be precisely the sort of thing we wished for in the SWTT (in fact legendary Mike Lowndes pointed to earlier signs of this move last month). It's also what I had my doh! moment about last week.
So if it's what I hope it is, we can co-ordinate with others in the sector on some standard fields (and keep it simple initially), push our content into Yahoo! and build apps on top of their search engine. My reservation would be that at the moment it seems to be about building either "Infobars" or "Enhanced Results", but perhaps there's something more API-like and programmable there, or on the way.
* is this the right way to punctuate the possessive of that annoyingly-punctuated name? Answers on a postcard (to Jerry Y!ang).