Like many others, I found these new earpods sound much better, but fall out. I actually bought these off the shelf to replace the Phillips in-ear headphones I was using (which use rubber tips to stay nicely in the ears, by the way.) The earpods fit in my ears, but because they are so slick, they will wiggle loose.
I managed to create a temporary fix by wrapping a few thin strips of double-sided tape around each earpod. Two strips each about 3mm wide seems to have done the job, they definitely feel more firm. Not sure what will happen in time, as the tape becomes less sticky and/or coated with skin oils and ear wax. At least it's cheap to replace.
An ideal solution would be some kind of spray-on rubber, which would only add a fraction of a millimeter in thickness, but would change the slickness of the plastic surface. Does such a thing exist?