If the opposing player happens to play this combo, does it happen to reveal the minion automatically? If not, what can you do against this fiendish combo other than wasting all your AOE cards?
A minion that is in stealth and given Taunt by another card will not act as a taunt until it comes out of stealth.
3I scared the crap out of a player that had never seen that "synergy" before. It scared him out of attacking at all! However, with the current version of the game, stealth + taunt has a special image that helps players see that the taunt is not active (it is faded and smokey.) Apr 19, 2014 at 15:23
Update since the answer was posted: HS updated its visuals to reflect this. A taunt stealth minion will have have a faded shield, to indicate that the taunt is disabled.– FlaterJun 20, 2014 at 10:40
In short, nothing happens. The taunt can be applied to the stealthed minion but it will not be a valid target for the enemy to attack so it will have no effect until the stealth is removed.