In my current project we have to develop a good looking desktop based application in java.
Currently, we have a very basic desktop application written in swing and team
Don't touch JavaFX 1 with a bargepole.
JavaFX 2 however looks very promising, with Oracle saying they're going to integrate it tightly to Java 8. It's got a very nice API behind it, it's graphically accelerated, you can skin it pretty much how you please using CSS3 and by default it looks pretty nice too.
Only caveat is that it's not available for Linux yet at all - but if you're looking to develop an application that's going to be released in the next couple of years or so, or you're not too fussed about waiting for cross platform support, it's a good option to consider.