I'm really starting to struggle to think of a reason NOT to use this for LOB apps.  Been playing with the VHD for the past couple of days and it feels solid.  I had dismissed LightSwitch as a toy when it came out, and my biggest reservation was that it used only Silverlight for UI.  Obviously neither of those things are true now.  Oh.. and that is a nice shirt: helped keep my attention through the whole video.