I have checked-in all the changes necessary for .NET MF 4.1 and Visual Studio 2010 support. Have a look at the project source code page.
You can download the latest release here (including the LE / BE files):
There are some complaints how the project is organized. The initial projects are done for desktop .NET Framework. As there are only little changes necessary for the .NET Micro Framework I was using the same source code files for the desktop and .NET MF projects and added compiler switches MF to get rid of missing support in .NET MF.
The .NET MF projects are prefixed with "Micro", if you want to use the MicroIO project in your .NET MF project you need MicroIO and IO, if using MicroHTTP you need MicroIO, IO and HTTP, too.