Support asynchronous operations (CRUD, Actions, Interceptors)
Currently, the main threads block completely on I/O and it's impossible to let the framework reclaim them to process other requests when using other threads for heavy computations (though I guess I/O generated by the providers to the backends are the most common culprits here).
This typically affects requests/sec rates as soon as a couple of requests require a longer time to complete.
Some providers already make async interfaces available, including the Entity Framework (since v6), the main provider for WCF Data Services.
It would be great to be able to take advantage of those.