While the ability to counteract styrofoam pollution is of course good, sadly this doesn't apply to other plastics in general. Some plastics are physically hard or chemically much harder to break than polystyrene (PP, PVC, ABS, anything that it fiber reinforced) .
So, while the worms are nice, one should not hope they can help with other plastics.
On the plus side, this does show that all the plastic we have put into the environment has been a niche energy source just waiting to be exploited.
Now think about all the plastic surface area in the oceans and stuff, I bet there are other things, bacteria and microfauna, which are actively adapting to consume it.