Keep in mind that there may be situations where an object may look to be stationary, but it's really moving with a small velocity (say, .2 pixels per second). I think with the physics behaviour, (and correct me if I'm wrong) a situation where a previously moving object is completely stopped could be rare.
Considering this, having a range of speeds that are considered as "stopped" (say, less than 1 pixel per second, greater than 0) may provide better results.