Edit 2014-11-14: From this blog post, a somewhat speculative plot of the bouncy landing, showing how close Philae might have come to tumbling off Churyumov-Gerasimenko and into space.
It’s believed that Philae bounced twice – the first bounce took about two hours, and the second one 7 minutes. As expected, the comet’s lack of mass and consequent lack of gravity has been a big challenge. At this point, it’s believed that the lander may be lying on its side, making a harpooning attempt out of the question. The drilling maneuver currently being carried out may push the lander upright, or out of the little sunlight it’s been getting, or even entirely off the comet, but there’s no way to tell just yet….