I'd say there's two reasons:
1) to make it easier for the movie to go with a new look (this might even be it...photos of Cavill in costume should be in our near future)
2) to distance the character from his origins at the hands of Siegel and Shuster. Note the announcement that some characters will have their origins re-done, this time I'm guessing more than cosmetically. I think we are seeing the first steps toward separating Superman into two entities: one controlled by DC and the other by the Siegel heirs.
Either way, as always, I'll leave it to you guys to let me know how it goes. If it's decent, I may pick up a trade in a year or so. Or not.
This is what I feel. I've thought for a while that DC was going to drop the elements their lawyers says the Siegels own rather than split the American profits with them. I do think we are ultimately going to see two different versions of Superman much the way (at least for a while) there was a Marvel version of Captain Marvel and a DC one.
I find it difficult to believe that DC will drop Superman entirely if they couldn't reach a deal wit the Siegel heirs or that they would revamp Superman again in 2013, which seems to be the cutoff point when the rights totally revert.
Again, the key is what the Warner lawyers say should be changed. Keep in mind DC has trademarked Superman, Clark Kent, Lois Lane, and various other things (including the S shield). As DC could call the original Captain Marvel "Captain Marvel") inside, DC may very well be able to use a number of elements so long as they alter various things from the Shuster/Siegel original version.
