The freedesktop action in nautilus-home.desktop is not currently available unless there is also an empty X-Ayatana-Desktop-Shortcuts= line

[Doug McMahon]

In other words the Actions=Window; is not being seen in the quicklist (Open a New Window

It will however show up if there is an empty X-Ayatana-Desktop-Shortcuts= line

So this currently works to expose the quicklist item

................
X-Ayatana-Desktop-Shortcuts=
Actions=Window;

[Desktop Action Window]
Name=Open a New Window
Exec=nautilus
OnlyShowIn=Unity;

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: nautilus 1:3.3.91-0ubuntu4 [modified: usr/share/applications/nautilus-home.desktop]
ProcVersionSignature: Ubuntu 3.2.0-18.28-generic-pae 3.2.9
Uname: Linux 3.2.0-18-generic-pae i686
NonfreeKernelModules: nvidia
ApportVersion: 1.94.1-0ubuntu2
Architecture: i386
Date: Sun Mar 11 21:28:35 2012
GsettingsChanges: org.gnome.nautilus.window-state geometry '800x550+58+24'
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta i386 (20120301)
ProcEnviron:
 TERM=xterm
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: nautilus
UpgradeStatus: No upgrade log present (probably fresh install)

[Jeremy Bícha (jbicha)]

Thanks for reporting this bug and helping to make Ubuntu better.

This problem is because Unity doesn't yet support the new Actions spec. I'm going to mark this as a duplicate of bug 942042.