I jump all the time with my clipless SPDs. I've hit a few big drops but thus far none sucessfully
Look into a pedal with a big platform around the clip component that way you can unclip and still have some pedal to push on if you feel you need to unclip.
I'm looking into the Crank Brothers mallet or similar so I dont have to be clipped in when I hit some bigger jumps and what not...