Doryuuzu wouldn't be nearly as good if he got Shell Break instead of Swords Dance.
Also Shell Break Shelgon. You just watch. Game Freak will do it for the 3rd game just because they're Game Freak.
Yeah...as well as Shell Break Kakuna and Metapod who are possibly the best users of the move since they can still have a net positive with Iron Defense. They can also sweep with +2 Bug Bite. -.- lol if this did happen, at least Beedrill would become another Shell Break Passer...
But seriously, lol Shelgon would acutally be pretty deadly if he got Shell Break. I hope Kingler and Crawdaunt also get this move, especially Kingler, who'd rape with it. And also, here's to hoping that Marowak's skull counts as a shell, thus giving him Shell Break!
The only way I can see something like Clamperl sweeping with this is if he comes in on a
really weak Bug, Ghost, or Dark-typed move to raise his Speed with Self-Conscious, and then goes for the Shell Break while not dying in the process. Otherwise he'll be way too slow, even after a Shell Break.
This is in standard play, of course. In Little Cup, that's another story. Once Self-Conscious Clamperl gets released if it's not already, then I kind of wonder whether Clamperl even needs Shell Break to sweep. Just come in on a Bug, Ghost, or Dark attack, which isn't too hard since Clamperl's defenses actually aren't bad for Little Cup, and go for the sweep with +2 SpA, +1 Spe if you have DeepSeaTooth.