Really, I hate the removal of the red portion of the tights. It's an iconic symbol of Superman that's been there for the better part of 80 years. Why get rid of it now.
Oh, because it "kinda, sorta, looks like underwear if you think about it a certain way and squint."
I certainly wouldn't have minded if they kept the trunks, but by this point I've gotten so used to his new look (both in the comics and the new movie) that the trunks really ARE starting to look a bit silly to me.
Especially in live action. In comics, I think they still work perfectly fine, because you can get away with much crazier outfits and designs there (like all those skimpy female costumes, which would look cheap and trashy as hell on a real girl).