Add-Type -Path "C:Program Files (x86)Reference AssembliesMicrosoftMSBuildv14.0Microsoft.Build.dll"

$slnFile = [Microsoft.Build.Construction.SolutionFile]::Parse("<path_to_solution>")

$slnFile.ProjectsInOrder | Where-Object { $_.ProjectType -eq "KnownToBeMSBuildFormat" } | % {

$outValue = $null
$found = $_.ProjectConfigurations.TryGetValue("Debug|Any CPU", [ref]$outValue)

    if($found)
    {
        if($outValue.IncludeInBuild) # This bit is set by the MS code when parsing the project configurations with ...Build.0
        {
          #Do stuff here
        }
    }
 } #End collection iterate