I saw this on Tuesday. Liked it. Didn't love it. The movie is being called a "requel" which is pretty clever. It is either Superman II or III (V.2). The fact that Luthor knows his way around the Fortress of Solitude would, to me, place it after Superman II. There's also another plot thread in the film that could only arise from the events of Superman II. If you've seen it, you know what I'm talking about. The effects are very good, Brandon Routh really channels Christopher Reeve in a fantastic way. Despite some online chatter that Kevin Spacey is merely mimicing Hackman's Luthor, I son't see it at all. Spacey is doing Spacey. He's slightly humorous, but also the creepy, scary guy we've come to expect (although 5 years in the joint will build a grudge).
The problems I have with the film are many. For one, there's only one surprise in the whole film. The rest of the film plays out rather predictably and doesn't offer much new. In its attempt to be a loving homage to the original, the film spends too much time recycling dialogue lines from the original movie in "wink-wink" fashion. For some odd reason, the music doesn't seem to connect and rouse the audience like it should, either. Although the composer incorporated several of John Williams' themes into the score, he must've dropped the ball somewhere in the arrangement. It just didn't lift me up like I would have expected. Of course, the movie is too long, as is the trend these days. And for all the talk of new dialogue and unused footage from Brando, I can tell you that this was not the case. Every Brando voiceover was lifted directly from Superman The Movie, and they were far less effective this time around when taken out of context. In the original, the image of Jor El almost seems alive, conveying love and knowledge to his son over a period of 12 years IIRC. In this film, it is simply a mindless hologram that will give up its secrets to anyone who walks in the door. Of course, Superman II had the same nitpick for me. Mty other question is why wouldn't the Fortress of Solitude have any security? I'll bet in the comics it does. I liked the plane crash sequence, but didn't care for the inclusion of a new shuttle system, since we know we're still a decade away, it requires an even further suspension of disbelief (same as Superman II moon landing).
So in closing, Singer has given us a beautiful looking, mostly recycled, sort of feel good, middle of the road Superman pic. Having stood in line for the first showing of Superman the Movie 27 years ago, I was a little disappointed.
I'm hoping the inevitable sequel breaks some new ground.