VS2012 does not support Silverlight 3.0
Not sure that this post really needs anything more than the title. If you are upgrading a Silverlight project from VS2008 or VS2010 be aware that VS2012 only supports versions 4 & 5 of Silverlight. If you need to update the solution/projects to use them in VS2012 I’d recommend upgrading to at least Silverlight 4…