My worst fears:
1. There is a scene in which Clark walks away from helping someone because he doesn't want to be a hero (ala Spiderman 2).
2. There is any indication that the only reason he is Superman is cause his father tells him to/because it's his destiny
3. There are no scenes showing his lightness/sense of humour/love for life and he spends the entire movie being pensive and serious
4. He kills a living being, accidentally or on purpose.
5. Lois is too nice (weird one, but if this woman doesn't have an edge to her then it's just not Lois Lane
6. Too much cgi, and badly done (I keep thinking of Sucker Punch. As much as I liked the film, I didn't like a lot of the cgi
7. Michael Shannon's performance will be diluted because of the overuse of cgi costumes for his character
8. There is a nano tech or other weird explanation for his suit fitting under the clothes and/or there is some tech that changes his appearance when he puts on the glasses.
9. Henry Cavill's performance or accent is jarringly bad
10. I think the movie is incredible, both as a Superman fan and a movie goer in general - but it gets horribly unfair slating reviews and a terrible box office