rabbits hop with the hind legs exclusively. front legs are for keeping chin off the ground only. shoulders never above hips. also, try throwing the weight around like they do with those bouncing ball tutorials - they aren't just about balls!

so this sketch is totally LOL but basically - jumping with the hind legs which push the body forwards. this also is a hop (walking) - loping (running) involves much more air time and the feet come much farther forwards.
while sketching i was reminded of http://www.youtube.com/watch?v=dSn2aZG9eB8, if anyone is familiar/was young in the 90's 
Okay, I think I get it, I'll just recapitulate to be sure... (by the way, your sketch really made me go WTF at first - looks like some retarded pig

)
Animation-wise, let's say when I'll redo those keyframes :
* the first one would stay the same (I guess the starting position is okay...)
* the second image would be the rabbit leaning forward, his hind legs fully stretched (or almost) and his front legs slightly off the ground. The body would be quite streched and slim.
* the third image would be the the rabbit only slight leaning forward, his hind legs slightly off the ground, getting ready for the next jump (cranked up or whatever you may call it), his front legs on the ground. The body would be compressed and "fat".
That's what I could understand from those "weight transfers" you were talking about (the elastic movement of the body). Or is it more for the muscle of the hind leg compressing and stretching ?
Sorry if I didn't make the keyframes to illustrate it, don't have time right now and I wanna get things straight first (will probably still give it a try tommorow anyways)