Hmmm. 40% chance of paralysis with damage included Vs. 100% chance of paralysis with no damage included? I suppose body slam could help for anybody who decides to switch to a pokemon immune to T-wave like gliscor, swampert, flygon, hippowdon, and any others immune to it. It could prove useful and if it doesn't too much, then there's always TWave to take Body Slams place on the moveset. I guess it depends on how you want to spread paralysis to your opponents team regardless of attack power. :/