Download WSP files

$dirName = "c:\newwsp"
Write-Host Exporting solutions to $dirName
foreach ($solution in Get-SPSolution)
  {
      $id = $Solution.SolutionID
     $title = $Solution.Name
     $filename = $Solution.SolutionFile.Name    
     Write-Host "Exporting ‘$title’ to …\$filename" -nonewline  
    try {    
      $solution.SolutionFile.SaveAs("$dirName\$filename")  
       Write-Host " – done" -foreground green  
   }
       catch    
  {
          Write-Host " – error : $_" -foreground red
      }
 }