there was a rumor going around during the marketing of Superman Returns that one of the reasons the suit was so dark was because it hadnt been used in a logn time, so once Kal-El donned the suit again, it started to "activate" again, as if the suit was returning to its former glory or something- i do remember Showtime at one point mentioning that to me, and, if i remember correctly, he kinda wanted to see something like that... of course, this was only a rumor, and proven to be false, but i can see the interesting part of that concept.
i'm completely against the whole "burst of energy from the shield" concept, but i wouldnt mind seeing the suit get brighter along the way, or, at least, more vibrant in color... look at Superman III, his costume changed because he became more evil. what if Superman's costume started to give off a slight glow around him, because his costume started to visually reflect the way Superman saw himself in the world, how he chose to live, what he did, the choices he makes, that sort of thing?... i've always liked the idea of the costume changing in appearance because of the actions and choices the person wearing it makes
the one thing i liked in STM was that when they started filming, the flying sequences, the dialog sequences, walking sequences, because of the equipment they were using, it gave the costume itself a slight unearthly glow around it, especially in the red part of the suit. I wouldnt mind seeing that again for this film, but i fear we wont be seeing that again, with the look that Krypton is going to have... and it's a shame, too. it has a more rustic and steel-like approach than anything, and i think thats going to echo in the suit.