Well, without wasting more times lets go to the main point,
Download Dust theme (.tar.gz)
(Updated September 10) Untar this file to ~/.themes and select it via System -> Preferences -> Appearance.
For Hardy, this theme requires Murrine from SVN. Compile it using:
sudo apt-get install subversion intltool libgtk2.0-dev libtool
svn checkout http://svn.gnome.org/svn/murrine/trunk/ murrine-svn
./autogen.sh --enable-animation --prefix=/usr
make && sudo make install
The wallpaper? No problem, here is the wallpaper download link
Other Cool stuffs to try
The mockups have borderless windows. To have this, go to your theme’s settings (Under System -> Preferences -> Appearance -> Customize) and under the “Window Border” tab, select “Dust Borderless.”
Try setting your panel background (right click at panel -> Properties -> Background -> Background image) to ~/.themes/Dust/panel-background.png.
Compiz decorator settings
If you’re using Compiz and you find the titlebar transparency weird, you can try running the script Dust_compiz_settings.sh (included in the download) to fix.