Now that SWF files are easily playable on computers running GNU/linux, I'm able to develop and debug SWF movies that I create using ming.
This is really awesome. Actionscript is quite an easy thing to script with, and swf movies have ajax functionality built in. I hope that Adobe continues to support swf playing on linux computers as it really helps me develop swf files!
I've been working on a swf (flash) slideshow, which includes links for each image. This is possible with javascript, but its nice to have an alternative. And if the needs for interactivity get really demanding, swf and actionscript can deliver a pretty consistent experience across multiple platforms. That's quite helpful!
Javascript libraries like jQuery help javascript maintain consistency across platforms, but it still has a long way to get before its ready for action like swf and actionscript.