The Curse of Superman has been something people have talked about for a while. I think Benbella books The Man from Krypton had a chapter about it (titled "A Word of Warning for Brandon Routh). Anyway, this piece for Business Day online by Phil Altbeker is about the curse, and seems to be the most comprehensive statement of it that I've seen.
I didn't write about the curse at all in my book. It's not really about superman in the way that certain jokes or the Superman Celebration is about the character. It's about the actors. Additionally, I've never heard it mentioned outside of the media, so it's really not folklore (as far as I can tell). I suppose if somebody wanted to explore it, the best place to start would be to talk to the actors themselves, see what they've been told.
Then there's this curiosity over at the AV Club: a defense of Superman returns by David Sims. I disagree with everything the article asserts about how the story was handled, but in the end what I really take issue with is this line:
The Christ/angel imagery is inescapable (at one point, Supes falls from
the sky, his arms outstretched as if he’s on a cross), but what else
could you possibly be looking for in a Superman film?
Maybe Sims doesn't think that people could be looking for a Superman story in a Superman film.
From a while ago, a review of Man of Steel that seems worth reading by Timothy O'Neil.
Another review of the same movie that seems worth reading, by Justice Carmon. Takes the opposite perspective.
That's about it.