If it weren't for those decks you might be able to afford to tech against it. There are a few neutral options you can make(aoe silence, scorpid to name 2). The real problem is the fact that the swaps can copy or (or have charge in wild).
Priest is bad enough as it is. That said if switcheroo had to be changed I'd rather see it have a "if your deck still contains minions" clause to get rid of the tutored aspect.
Great writeup of the card. I agree it has the potential to be a problem just right now there is no place for priest in high ladder. In a week or two when we see some nerfs/buffs I think there's a good chance it will see some relevance.