In previous versions of JavaFX there was support for Linux. When Linux was supported only official support was provided for Ubuntu, which is fine since the majority of users use that Linux distribution. Although the media stack for Linux was in Beta it managed to be reasonably stable enough for production use.

With JavaFX 1.3 Prism was made available for Linux, therefore there shouldn't be too much effort involved with migrating the development to JavaFX 2.0.