While early word was that the movie was an unqualified success, reviews haven't been nearly as kind: as of late Thursday afternoon, the movie was on the border between fresh and rotten on Rotten Tomatoes. For a movie of this scale, though, mixed reviews aren't typically an issue on opening weekend, and that should be the case for Man of Steel as well.
Adjusted for ticket price inflation, Superman Returns's five-day opening would come in at around $102 million. While that was very highly anticipated at the time, it's safe to say that Man of Steel is generating at least a bit more buzz. It's also important to note that the marketplace has made room for Man of Steelno title in the past two weekends has opened higher than $34.3 million, and none of the holdovers will gross more than $15 million this weekend.
The current record-holder for a June opening weekend belongs to 2010's Toy Story 3 ($110.3 million), though Transformers: Revenge of the Fallen had a higher three-day start ($127.8 million). While both of those movies had the sequel advantage, Man of Steel also has an established brand, and has at least as much excitement surrounding it. Therefore, an opening in that range seems like a lock right now.