Swing seems to be en vogue at the moment, whereas not long ago it was SWT that was fashionable.
I’ve never developed with SWT before, but I’m finding that there’s less reason to do so now that before. JDK1.5 enhanced the Windows look and feel to make Java apps look more like Windows native apps. If you want to take it a step further, you can use something like the Plastic L&F which will give you excellent results.
I’ve no doubt you can get similar results with SWT, but is it worth it? I’d be interested in other peoples opinions. Do you develop with Swing or SWT?