IMO its doesn't fit current Superman for 2 reasons 1) With the cape it makes the neck area too busy. I like the high colar on Hal and Aquaman who are capeless, but I don't think it fits here. 2) It's a bit militaristic and doesn't fit well with the whole "working class hero" Superman has in the DCnU (which I like by the way, he's more neutral good, not so lawful good). On the other hand Hal is part of a Corps and Aquaman is a king, so militaristic elements in their costumes fit better.
But to each his own.
Yes I know. I'm kidding. Sorry can't help it.
Today we have wrestlers and their Championship belts are one of their characteristics. So if you want to remove the trunks you can give Superman a wider belt (something like the one in Earth-2 but a bit wider) with the same color (red and yellow, I don't like the only-red belt). That way you get rid of the trunks and stay true to their purpose in a way. But that's just me...