Are there plans to support all of the analysis extensions through the REST API, it seems like the network functionality is making its way here, but what about all the spatial, 3D, and geostats capabilities. Are there more updates coming with beta 2?
No other extensions are planned on being supported out of the box at 9.4.
We will support custom SOEs through REST though. So if you wrap the functionality exposed by these extensions into a custom SOE and implement a certain interface, it can be exposed thru REST.
Another option of course is to wrap it in a GP model and make it available as a GP service.