For reference and for anyone who stumbles on this post looking for compatible plugins, here's a list of older photoshop plugins that work as live filters (non-destructive) in Fireworks CS6.
Alien Skin Eye Candy 5 Series: Impact - includes various effects like advanced bevels, glass, motion trails, advanced shadows and a lot more
Alien Skin Eye Candy 5 Series: Nature - imlcudes effects like fire, smoke, water drops and a lot more
Alien Skin Eye Candy Series: Textures - varioous texture effects with advanced customisation features; wood, metal, brick, marble etc
Alien Skin Eye Cany Splat v1 - add avanced textures, fills, patterns, borders and edge effects .. very large range of options and very versatile, although Fireworks textures and pattern fill integration is excellent in itself.
Alien Skin Xenofex 2 - various effects and filters for creating jigsaw puzzle effects , lightening, flags, crumple and ripped paper, burnt egdes and a lot more...
Alien Skin Snap Art 1.0 - Turn images into realstic artictic pictures, includes effects like pastel, comic, water colour, pencil and a lot more with advanced features for fine tuning
Alien Skin Bokeh v1 - Bokeh effects with lots of features to adjust the Bokeh effect
Alien Skin Exposure 2 - Colour and B&W adjustments/effects for photos
Another interesting plugin is Alien Skin Image Doctor 2 it won't work as a live filter as you have to create a selection before you can apply an effect,. It does image repairs to remove scratches, smooths skin, JPEG repairs etc and one tool which is really interesting is the 'smart fill' tool which works just like the content-aware fill in Photoshop.
The Alien Skin plugins come with lots of advanced features and the ability to create and save you own presets after making your adjustments. Of course these are older versions so if you wanted them you could try aproaching Alien Skin to see if they will sell you some older versions.
These plugins also work as live filters in Adobe Fireworks CS6:
Neat Image works as of v8.4 (you need the home version as it works better than the pro version believe it or not)
AV Bros Puzzle Pro 3.1 - jisaw puzzle effects with adbavced custmisation
AV Page Curl Pro 2.2 - Advanced page curl effects
Virtual Painter 5 - Turn photos into artistic impressions (like Alien Skin Snap Art) - Dissapeared a long time agao
The PluginSite's Plugin Galaxy - Includes a vast range of effects and filters.
The PluginSite's HyperTyle - Advanced edges, textures, surface and fill effects - extrememly versatile plugin **Note one slight glitch when launching the plugin it will launch its windows behind the Fireworks main window, a minor inconveneice for a very good little plugin.
Frischluft Flair and Lencare plugins both work as live filters
I also think most of the Redfield and Flaming Pear plugins work as live filters in Fireworks CS6
StarFilter Pro also works as a live filter but only in auto mode (the manual editing does not work)
You'll also find numerous plguins that will work but NOT as a live filters;
Lens Flares: the Old Knoll Light Factory v2 works and there was an old little lens flare plugin that dissapeared a long time ago caled Axion Lens Flare both of these could add lens flare effects to Fireworks CS6. Other older plugins that used to work (but not as live filters) were the earlier Andromeda plugins too and you'll find a lot of other older photoshop plugins will work but probably not as live filters.
New phopshop plugins tend not work well or at all in Fireworks, as Adobe has updated the plugin architecture whilst Fireworks has not been updated for some 5 or 6 years (sadly) as it was EOL'd by Adobe.
Something very useful also but not a photoshop plugin is the Linked Images Panel ..... Compatible with AI and PSD formats .... Works a lot like Smart Objects in Photoshop insert a PSD or AI linked image with the panel ... update the linked image in PHotoshop or Illustrater, save and then it updates in Fireworks with the help of this panel. Its really useful .....