It looks like the cakewalk FX plugins and some others in the cakewalk line will not work in Soundforge 8. When you load the plugins while in Soundforge, there is a message that tells you that,
"This Plugin is only liscensed to be used in Cakewalk Sonar. An unrestricted version can be purchased from www.dspfx.com" You will have to go through them to find out which ones don't work, there are too many.
In addition,
Lexicon Reverb doesn't work, some of the Project 5 plugins don't work,
All 32 of my Waves plugins work fine.
The Wave Arts Track plug works fine.
Timeworks EQ and Compressor work fine
All in the Voxengo Mastering suite works well.
PSP Vintage meter works that's all I 've checked so far.
ALL Sonitus Works
BBE Sonic Maximizer works
SSL Oxford Mic compressor plug in works
There are more, but I am tired of testing plugins, beside I mainly use the Waves and Voxengo with Soundforge 8.
Peace