ok Lets get into it.
I have now developed a quick demo application that displays maps. It is something of a combination between Google earth and Google maps. Hopefully I will find time to take a screen capture and get it online. I also have started a project for doing code reviews. It is still very much in its infancy but it gave me a very different point of view on JavaFX.
I have to say that I have really enjoyed the experience thus far. JavaFX is nice language for building UIs. I really like the combination of declarative and functional aspects of the language. My current favourite systems language is Scala and coming from there (and from Java) to Javafx was very natural and I was able to get up and running very fast.
The tutorials are very helpful in getting going as well. Adding wiz-bang and wowzer effects to an application is a real no-brainer and having property support into the language is absolute genius.
If you want to play around I would highly recommend taking a look at the samples. They are some good examples and the code is right there to show you how you can pull it off.
I did most of my development on Ubuntu so although linux is not officially supported it is not a major issue so don't hold up over that issue.
At this point Javafx also has some warts. Although they are all easily solvable and I am sure are simply here only because the system is a V 1.0 product. The only really major issue I encountered was the sever lack of widgets. Yes swing can be easily used... but swing is in no way a nice way to do UIs. This aspect MUST be fixed or Javafx will be no more than a Swing replacement, if that.
I also experience some compiler bugs but when I went to report them I saw that they were not only reported but already fixed and schedule to be included in the next release. So that really does not concern me.
The last issue is the netbeans support is only decent. Code completion frequently fails and there are occasional unpleasant behaviour. Nothing major and now that Tor is on the job I am sure that will be very nicely fixed up.
In short I have to say that I am VERY excited about Java One this year. I am hoping for another big JavaFX release. Hopefully it bring some widget libraries to the platform.