The GeoPlatform is built on Esri's open-source Geoportal Server. Even though it looks like ArcGIS.com ...
... it's running Geoportal Server under the hood. That means it should search geospatial metadata. Since it's federal, it also federates -- harvesting and indexing metadata from many geodata servers. Then it runs a federated query across all servers to find data you want.
So why doesn't anything show up when you search for 'chesapeake' ?
You have to click the "Related Searched" link farther down the page. Now you get the dozens of results in a format that looks familiar to anyone works with metadata and geoportals:
The search engine is reaching back into the geodata.gov and data.gov metadata domains.
Why is the search function like this? GeoPlatform gurus say it's only temporary - a work in progress. In my view, it's intriguing work to merge the best of FGDC/ISO-compliant metadata + geoportal search capability, + web mapping provided by the Esri web mapping APIs. More on that in my next post on geoportal news coming out of the Esri FedCon this week.