One of my saved searches for "OpenSearch" turned up this job posting on Craigslist for a server-side software architect at Groxis. OpenSearch is listed along with REST, SOAP, XML-RPC, RDF, and RSS as something a candidate will have a solid knowledge of.
It sounds like a kick-ass job at an up-and-comer in the search space. Groxis is definitely pushing the envelope in the syndicated search space.