Alice posted her wrap up notes on the WorldCat Mashathon event about which I blogged a couple of weeks ago. There is a nice video of Alex talking about the prototype we did on the spot.
Adding WorldCat to Windows 7
WorldCat Search API
to add WorldCat-formatted citations and links to the Windows 7 environment, which has native search federation functionality built in through OpenSearch. They then added book covers for visual interest (through a separate covers service). Next they will add geolocation mapping functionality so users can find their local library through a Silverlight-based mashup with Bing maps.