Turborilla (me) is currently developing the game Mad Skills Motocross, and you might be interested in checking out the developer diary. It’s a monthly thing and has been going for five months so far.
I am using jMonkeyEngine for the graphics and a bunch of other stuff you can read about in the diary entries. The latest entry (November) is all about the level editor, and has some screenshots and a video.
find them all here: http://turborilla.com/developer-diary/
Any questions? Fire away, I lurk in this forum daily