OK I am totally w/ Prime here.
Amphy being stackable would be crazy.
I believe this COULD have a very SLIGHT chance of being the new NEO GENESIS SLOWKING for the format.
It is quite similar because Slowking was stackable and made your opponent not want to use trainers AND it even had IGGLYBUFF which could shut down its power, but it STILL dominated.
Amphy is stackable and makes your opponent not want to play supporter and it can be shut down by LatiLock.
Igglybuff couldn't stop King, so I dunno if LatiLock is enough to stop Amphy.
At the same time, I haven't seen the rest of the set, but I am pretty sure this is gonna be played.
EDIT: I keep looking at the spoilers and I just don't see how it could not become an archetype. Absol ex+this+searcher (Queen/Fearow d prolly). I mean you can even use Amphy d. to turn all your pokes delta in order to be able to abuse Casty and Fearow d.
Think of it w/ Absol. You have 1-4 Amphys out (will just use 2 as a realistic mid-game example). Your opponent plays a supporter. You put 2 damage counters on each poke. Next turn, you drop Absol move some damage around and hit the bench again for 10. NOW it is getting serious. If the opponent plays a supporter then each benched poke will have 50. Enough to kill a few basics, and it prolly isn't gonna stop either.
I know that I am prolly exaggerating a little, but it really has never been hard for decks to set up 2-4 Stage 2 pokemon (ie. LBS, Flygon, MetaNite), so I don't find it much of a feat to get out a few Amphys and just spread damage everywhere. People are gonna be scared of supporters, and Absol ex is just SICK w/ this card. LatiLock could become staple and this deck could very well be the next Slowking, but don't mark my words on that. I am just making crazy predictions.