.Net 3.0 and 3.5 out of support April 12th, 2011
If you have any applications that target .NET Framework 3.0 and 3.5 you need to start making plans migrate to .NET Framework 3.5 SP1 before April 12th 2011. The update to .NET Framework policy states that beginning with .NET Framework 3.5 Service Pack 1 (SP1) the .NET Framework will be defined as a “Component”. As a Component, .NET version 3.5 Service Pack 1 (SP1) will assume the same Support Lifecycle policy as its parent product or platform.
You can read more about the Microsoft .NET Framework Support Lifecycle Policy by clicking here and here.