Dropbox is being integrated into office 365 and other tools.  But the Dropbox company has no concept beyond individual user deployment.  This script is to install Dropbox for all users using a administrator or system account on Windows 7 or Windows 8.

Yes there are changes that could be made to make this more specific (program files vs program files (x86)) or other customization... but the script is just a start.

Hopefully Dropbox will see it and they will address their client design for a all users deployment.

----- Powershell Script... Enjoy. -----
$dropboxexe = "Dropbox 2.10.52.exe"

$allusersprofile = (gci env:allusersprofile).value
$appdata = (gci env:appdata).value
$arguments=  '/S /D=C:\Program Files\Dropbox'

$LASTEXITCODE = (Start-Process -FilePath $dropboxexe -ArgumentList $arguments -Passthru).ExitCode

$i=0
do
{
  $i++
  $ExplorerRunning = Get-Process explorer -EA 0 
  if ($ExplorerRunning -eq $null)
    {
    #if explorer stop restart it. 
    schtasks /Create /TN "DropBoxInstall" /TR explorer.exe /SC OnLogon /ru Users
schtasks /Run    /TN "DropBoxInstall"
schtasks /Delete /TN "DropBoxInstall" /F
    }
  $dropboxexeRunning = Get-Process $($dropboxexe -replace ".exe") -EA 0 
  if ($dropboxexeRunning -eq $null)
    {
    #if install is complete then stop dropbox.exe from starting
    kill -name dropbox -force
    $i=999
    }
  Start-Sleep -m 500
} while ($i -lt 200)

#copy add remove programs entry
Remove-Item -path "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\Dropbox" -ea 0
copy-item -path "HKCU:\Software\Microsoft\Windows\CurrentVersion\Uninstall\Dropbox" -destination "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\Dropbox"

#copy shortcuts
$PathFrom = "$($appdata)\Microsoft\Windows\Start Menu\Programs\Dropbox\*"
$PathTo   = "$($allusersprofile)\Microsoft\Windows\Start Menu\Programs\Dropbox\"
Remove-item -path $PathTo -recurse
md $PathTo -ea 0
copy-item -path $PathFrom -destination $PathTo -recurse