I have used the LightSwitch Beta to create a test application and I found it inferior to nHydrate in its data handling features.
LightSwitch does not have built in Auditing.
It does not support many-to-many relationships.
You cannot apply a Unique constraint on a column/property.
I am sure there are other shortcomings compared to nHydrate in data handling.
The data entry screens LightSwitch generates are a pleasure to use and it almost completely eliminates the tedium of creating a UI (of course beauty is in the eye of the beholder).
It has built in Authentication and Authorization (Windows and Forms) and a Permissions infrastructure that is easy to understand and use.
Being built on SilverLight you get the full trust desktop application and the browser based sandboxed web application with the same UI code.
It generates 2-tier and 3-tier desktop apps and 3-tier web apps.
The Beta download integrates into VS2010 Pro and you select a LightSwitch template like you would any other project template and in C# or VB.
The Beta is buggy (expected) but has enough potential to keep me interested.
My skills base is insuffient to be tester for you. I still do not know how to use RIA services. My background is VBA in Office Apps and I am just starting to learn C#. LightSwitch is similar to MSAccess on steroids that is why it is appealing
When I found nHydrate it just seemed like the easiest way to handle data that I have ever seen and now that I have found LightSwitch it appears to be the easiest way to build an application that I have ever seen. I am just not sure how to put the two
together or even if it is possible.