CSLA 3.0.6 to latest version 4.5.501

I am not sure if I posted this question before or somebody posted it, but somehow I cannot find the discussion.

We had lots of in-house applications that uses CSLA 3.0.6, .NET Framework 3.5/4, VS2010.  Would it possible to upgrade all of those to the latest CSLA version (4.5.501), .NET Framework 4.5 and VS 2012?

One our concern are there lots of validation and business rules in any of the project.

Thanks.