I downloaded the JavaFx preview from oracle home page. It's a zip file, I wonder how one could install it on Ubuntu 12.04 pc.
See the installation instructions on the JavaFX 2 release notes for Linux. http://docs.oracle.com/javafx/2/release_notes_linux/jfxpub-release_notes_linux.htm
To install: Download the JavaFX SDK zip file from http://www.oracle.com/technetwork/java/javafx/downloads/devpreview-1429449.html
Extract the SDK files from the zip file to a directory on your local file system.
There is more detailed info in these blog posts if you need it.
The blog posts also mention how to ensure that the correct codecs for media playback are installed.
I found it simpler to install a plain Oracle non-GPL Java 1.8 JDK on Ubuntu, JavaFX is included there and works automagically.