Wahaca does have authentic mexican food. It has authentic Mexican Beers and a good selection of tequilas. It does not, for some odd reason, have a single Mexican waiter (?!?).
Relative to other "Mexican" restaurants Wahaca is one of my favorite (second only to Mestizo). The tacos are spicy enough (if not add the Chipotle sauce), the mole is truly hand made.
Fantastic place to grab some real Mexican food after theatre or to go with a group of friends. Notice the no reservations policy though.