The secret is that the Wonder Woman who stars in this title is Donna Troy, the former Wonder Girl. Sometime in the year between Infinite Crisis #7 and this issue, Donna has decided to step in for the missing Wonder Woman. You may say "But that's not Donna on the cover," and you would be right. The cover is a red herring. It may also be a hint that the real Princess Diana Wonder Woman will be back soon, because...
Secret #2: At the end of this story, a government agent named Diana Prince shows up, and darned if she doesn't look just like Princess Diana!
So did I like it? Well, I'm intrigued enough to stay with it. And the very pretty art by the Dodsons doesn't hurt!
P.S. There's also a Secret #3: Tom Tresser (nemesis) is back from the dead and will apparently be a supporting character, at least for the first arc. I've always liked Nemesis, so that's cool!