For Q1 2013 we expect a huge update for Windows Embedded Compact (WEC7 v.next) that will also include a newer version of CompactFramework. Currently it is not fully cleared which development environment will be supported by this OS version.
If you are currently evaluating which VS verion you should use for your Windows CE/EC application development here is our recommendation:
As VS2005 is resticed in debug possibilites for .NET applications and also does not include support for an easy development of silverlight applications we currently recommend using VS2008 Professional version.
Just an update about which OS requires which Visual Studio:
Visual Studio 2005 Standard (c++, .NET CF2.0)
Visual Studio 2008 Professional (c++, .NET CF3.5)
Visual Studio 2012/13/15 Professional (c++, .NETCF3.9)
Windows 10 IoT Core
Visual Studio 2019 Professional
To get access to older Visual Studio versions you need a "Microsoft MSDN Subscriptions" license.