I have been playing around with JavaFX the last months and i would not recommend anyone to start using it unless the limitations (like lack of Linux support) are too harsh. The IDE support for JavaFX is ridiculous at the moment. You have no refactoring help, no autoformat and not even help with indentaion.
I like JavaFX and will continue to play around with it, but for 2 equally good languages, the huge IDE different is hard to overcome.
Silverlight has got Expression Blend as well, for (kind of) WYSIWYG.
I think a solution in JavaFX would be better, but creating it will probably be alot more difficult.
