Deffinately not a full grown shrimp, even a dwarf shrimp. They might get a few small ones, but really, dwarf frogs are such inefficient eaters it'll probably be a plus.
I have one in my shrimp tank right now and was worried about them eating my RCS. But after watching it try and get even the smallest babies I have to agree with the other posters. They are really slow at getting food. I have to dangle bloodworms in front of the frog or else the shrimp will go after it and snag it before him. In this tank I go through blooms of shrimp growth and have never really noticed any damage done by the frog.