The most common use will probably be InterpTrackMove objects, which have two InterpCurveVector properties, PosTrack, and EulerTrack. Here is an InterpTrackMove opened in the Curve Editor:
The view-port is automatically sized to fit the keys. The InterpMode for the selected key is displayed and changeable at the top (see here for explanations of the different modes). Each key can be dragged up and down to change its value. The handles on the selected key can be dragged to change the curve.
Opinion Solicitation Time:
Where would you like to be able to open this from? I stuck an option in PackEd's edit menu to open the currently selected export in the Curve Ed, but that was for testing purposes. Any ideas for a better place?
Like I did with the Sequence Editor, I modeled the UI on UDK's Curve Editor. Opinions on looks?
Any other thoughts on how you'd like this to work?