I've been really bad about keeping up with the news lately because we're in Europe with the on AIR tour but during our RIA Weekly podcast, Coté mentioned an article by Paul Krill which indicated that JavaFX is going to be releasing a preview version at the Java One conference in May.
If we really do get to see a version of JavaFX, it could be a big deal. JavaFX has kind of been the quiet one in the big three RIA companies (Microsoft, Adobe, and Sun). There has been a lot of speculation but not a lot of hard information other than sporadic bits of JavaFX mobile talk. In the podcast, Coté mentions that a lot of Java developers just want to build a better user interface. JavaFX could be a big, big leap for them to do that. Sun sees JavaFX as a way to create interactive content with one language across devices and desktops.
I think it's a bit difficult to place JavaFX in the general competitive space. As I understand it, JavaFX is analogous to XAML or MXML, it's more of a language enhancement that will be built into the Java runtime than something like a browser plugin or a standalone runtime. They're also looking to target the set-top box market which could be VERY cool to see. I think that space is ripe for RIA technology.