My apologies if this was already confirmed, if that's the case disregard this post.
Earlier in this thread, it was rumored that Explosion no longer halves the Defense of the target, and it's indeed TRUE.
Pokémon used for both tests:
Golem (Adamant 281 Atk 31 IV/0 EV) vs Cresselia (Bold 444 HP 31 IV/252 EV, 303 Def 31 IV/0 EV)
SelfDestruct:
_if old mechanics (266 - 314 HP / 59,9 - 70,7 %);
_if new mechanics (133 - 157 HP / 30,0 - 35,4 %);
against Cresselia, Golem's SelfDestruct dealt 139 HP.
Explosion:
_if old mechanics (333 - 392 HP / 75,0 - 88,3 %);
_if new mechanics (166 - 196 HP / 37,4 - 44,1 %);
against Cresselia, Golem's Explosion dealt 190 HP.
It means that now Explosion has really an effective base power of 250, and the same holds true for SelfDestruct with an effective base power of 200.
Wow I would have never thought SelfDestruct and Explosion to be nerfed like that.