It is simple display a .NET remote service's Array-based result in a Flex DataGrid.
Bind an ArrayCollection's 'source' field to the correct result in the service's model, and
Bind the DataGrid's 'dataprovider' field to this ArrayCollection.
For reasons noted here, bind dataprovider fields only to collections (such as ArrayCollection or ArrayList), not to 'raw' Arrays.
That's why this sample's client's DataGrid's dataprovider binds to an ArrayCollection (line 61), which binds to an Array (line 58).
Things to try:
Make mistakes on purpose, such as binding the DataGrid's 'dataprovider' field directly to the .NET service's Array-based result. What happens? Why isn't this 'best practice'?