Today I tried Dockbarx 0.42.1 the Windows 7 preview feature in my Ubuntu 10.10 Gnome and made it works in awn. For some who want to install Dockbarx applets in avant-window-navigator in Ubuntu, follow the steps what I just did below.

Step 1: Open up a terminal window from Applications -> Accessories menu, install dockbarx for the PPA (supports Ubuntu 9.10 and higher):

sudo add-apt-repository ppa:dockbar-main/ppa
sudo apt-get update
sudo apt-get install dockbarx dockbarx-themes-extra

Step 2: Install avant-window-navigator and awn-applet-dockbarx:

sudo apt-get install avant-window-navigator awn-applet-dockbarx

Step 3: Start CCSM at System -> Preferences -> CompizConfig Settings Manager, search and check “KDE Compatibility” and “Support Plasma Thumbnails” in its click-into configuration window (Alternatively you can use kwin as window manager instead of compiz. That will give you previews for minimized windows as well.)

Step 4: Finally, start awn at Applications -> Accessories -> Avant Window Navigator and add Dockbarx in its settings window Applets tab.

Note:
1. If you don’t see the Dockbarx applet in step4, you can download the source code from gnome-look.org, and then extract and copy the content of the AWN folder to ~/.config/awn/applets folder.

2. To be able to access DockbarX’s recent and most used menus for openoffice, you need update zeitgeist to a newer version. If you an older version of ubuntu than 10.10, you need to update zeitgeist to get recent and most used menus for any program.

sudo add-apt-repository ppa:zeitgeist/ppa
sudo apt-get update
sudo apt-get install libgtk2.0-0 libx11-6 libxcomposite1 zeitgeist

3. If you would like to remove the gnome default panels, read the step 3 in this post.

4. To configure Dockbarx applet appearance, head to Applications -> Accessoires -> DockbarX Preference

Screenshot: