If you are interested in RIA Frameworks you can have a look at that comparison http://sonymathew.blogspot.com/2009/02/comparing-ria-frameworks.html (Thanks to . ADF Oracle Faces RC you can find here, thanks to Juan Camilo Ruiz.
Unfortunately JavaFX as well as Microsoft Silverlight is not mentioned in that comparison. That's why you can find the "missing" JavaFX column here:
User Experience: Modest Rich if you're familar with Java. Is exactly like a Desktop App. No Page refreshes, all data-access & rendering in the background. Includes also data-bindings from variables to GUI-widgets. JavaFX wraps some Swing components to use them in a JavaFX GUI. JavaFX 1.1 API
Browser Support: Support all browser. You can deploy JavaFX applications via an Java Applet, Java-WebStart (JNLP - Java Network Launching Protocol) or stand-alone applications on the desktop.
Throu Java Web Start a one-click installation is possible. Awesome feature: You drag an applet from the browser to your desktop.
UI Code: JavaFX Scripting and Java. Via JavaFX you can describe your GUI in a declarative way. JavaFX allows to bind variables to GUI-widgets (data-bindings) and provide a possibility to add triggers to variables.
You can develop the business logic in Java. There's a plugin for different Adobe Tools (e.g. Photoshop) for designing your GUI.
Access Remote Services & Data: You can invoke remote Java-Services via RMI.
Code Complexity Management: JavaFX files (JavaFX Script Programming Language), Java files, Organize into Class/Object hierarchies, Packages. It's statically typed and a compiled language.
Tool Support / Eclipse Integration: There's a JavaFX Plugin for Netbeans. The plugin in provides Code-Completion, Live-Preview of the GUI and so on. Download page
Refactoring & Code-Completion Support: All Java Refactoring & Code Completion with NebBeans.
JEE Integration: You can invoke EJBs like in any other stand-alone Java-Application.
Migration: You can use existing Backend-Services. Of course you can use existing any Java-Code inside a JavaFX-Application
Performance: Partial downloading of the JRE is one of the performances pros. So you can use JavaFX-Applications on clients which haven't got a full installed version of the JRE. Modest download-time to browser because of modularized JRE (Entire JRE: 14,5MB but you need in most cases only the Typical Applet version 4,6MB)
Static-Content (Externally Managed): You can style your widgehts with CSS
Requirements: You need JRE 1.6 Update 10
Search Engine Optimization: Not compatible.
Currently J4Fry is working on some Dojo-Tags for Facelets for RIA feelings in JSF applications.
The declarative Tag should ease the use of Dojo in JSF Applications.
There'll be news about J4Fry-DojoFaces-Project when there's a beta version for testing.