The ArcGIS Server RESTful API will come out at 9.3, but what about those who need it now? Well Dave Bouwman has blogged about its release. Because we all love demos, here is the link to the ArcGIS Server RESTful API.
Notice that it is running on OpenLayers. Think about what you are seeing there. You’ve got the ArcDeveloper.net RESTful API to adding features to the map. The source data is stored in ArcSDE in SQL Server, and is accessed via the ArcGIS Server SOAP API. As Dave Bouwman says, “lean and mean, but works quite nicely with OpenLayers and VE”. That is exactly what many of us have been asking for over the last year.