So you are thinking Tatulla instead of Mists of Corrosion? i think mists definately have there place, sure they may have an equipment in hand that they discard instead, but you still got rid of there equipment.
If you play mists and they discard the equipment in hand instead of destroying the one on the board, you still need 1 more equipment remove item to get rid of what's on the board.
If you play Munkin, you destroy what's on the board, but they will just play the one in the hand, so you still need 1 more equipment remove item for what is now on the board.
The benefit i see to mists, is that it has a chance to work against all decks, and can also fuel searing light. where as munkin will give you a threat on the board. There are many ways to look at it, and both are decent.
I think i still like mists over tatulla simply for the versatility reasons. but tatula not only gets rid of something, but gives you a threat. i would like to hear further opinions...