Universal is practically guaranteeing MoS will gross north of $100 million for its OW. Obviously rival studios will say that because if it grosses less, they can state that it was a failure. The bright side to that is if it were to open at such an amount ($85 Million) is that the film could possibly have a 4x multiplier with good WOM. Either way, WB and rival studios expect this movie to land anywhere between $300-$350 million domestically at the end of its run. The foreign figures -- I don't think anyone has a clue how that will turn out. We could maybe see TDKR type foreign numbers such as $500-$600 foreign. Who knows.
Most will say MoS won't pull in a high amount overseas due to the character being so American. I don't buy it. Once again, people need to forget about Superman Returns. How many films do we have as a basis to such an argument as popularity overseas? SR was a disappointing film, yes but this needs to be forgotten and will be soon. MoS is being pushed aggressively as a totally different movie and a Superman we have never seen. The GA is going to eat this up.
With the state of the world (shootings, earthquakes, murders, natural disasters, corruption) people will likely turn to Man of Steel as a get away from everything. That's what people do when they see movies anyway. So -- this could result in a record breaking turn out.