ArcGIS.com (and existing arcgisonline.com) is built on RESTful api. We will be documenting the API and exposing it for public consumption later this year. The web map configuration will also be open at that time. We are working on having the Web APIs support the web map configuration out of the box. I cannot give a date estimate on that at this time.
Thanks for you interest! Jeremy
Will you publish the structure/format that defines map mashups on the new ArcGIS.com?
Will it be served by REST endpoints? Will the client APIs support it out of the box in the 2.0 releases?
Now that webmaps documents are supported by various technology like the Silverlight API 2.1, do you have the standard published (even some beta docs would be great)?
