As of today, the official release of Lightswitch is now available. Visit: http://www.microsoft.com/visualstudio/en-us/lightswitch or you can download from your MSDN subscription.
What is Lightswitch?
It is basically a simple to use application generator that can be used to build applications within minutes in many cases.
If you have an existing, well structured (primary keys, relationships) SQL Server database you are just a few clicks away from an administration tool and well on the way to a full fledged app!
One limitation is that you must be using SQL 2005 or above. I did verify this by trying to attach to a SQL 2000 db. Once the standard database connection dialog is passed you will recognize the entity framework screens.
There will also be lots of third party and community extensions that will simplify making full blown applications.
Code generated can be either VB.net or C#.
In many ways this reminds me of the ease of Access but brought to the level of professional development and extensibility.
Definitely check it out, a very powerful new tool!!
To get started even if you have limited programming experience, check out Beth Massi’s videos: http://msdn.microsoft.com/en-us/lightswitch/gg604823