Went with the bf about 6 months ago for Late Night Fondue--$40 for a bottle of wine (I think it was Yellowtail?), cheese fondue, and chocolate fondue. The cheese fondue (beer one) was great--we were really big on the apples and veggies and our server brought us more to dip without us even asking, no charge! The chocolate fondue was okay--we got dark chocolate but it was still overly sweet for my taste so the bf got to eat most of it. Still, considering MP's usual prices, this was a steal. They do Late Night Fondue the last hour before close, I think every day of the week (though their hours vary).
And thanks to PA law, you can get the wine recorked--we only drank half the bottle and were able to bring it home. If you want to experience MP but not willing to shell out $60/person for the full shebang, I definitely recommend the late night deal. Note--this is a PGH-only deal. Other cities have other promotions, so watch out for that!