Not right now, it's not really an option for the type of things we do.
I know Premiere Elements on windows (that's what $99?) is supposed to support our plugins... not sure they will release a Mac version once the CS3 rollout is over.
For your information,
FCE might share the same source code as FCP but lags some dot versions before what makes it in FCP comes to FCE
So at some point Twixtor FxPlug will start to work in FCE (the changes Apple did so it works will be part of the build) - At that point we will add FCE as supported application.