@The Poet: I agree that The Riddler's question-mark mohawk was a bit silly, and I had a similarly negative reaction to the one you had upon seeing that in the previews of the first issue (though apparently not nearly as strong). However, I read an article where either Scott Snyder or Greg Capullo (or both) explained the justification for that weird hairstyle, and I thought it was kind of clever and inspired. They explained that because the inmates of Arkham Asylum were stripped of their trademark costumes and get-ups and forced to wear simple jumpsuits, they had to create makeshift costumes in order to continue being their criminal personas in that environment. If you look, you can see that Professor Pyg's mask is made out of sheets and the eyes on Scarecrow's mask are made out of buttons.
So though it was kind of silly, I thought it was a smart way to show their insane need to be recognized as their outlandish criminal identities rather than as mere people. After reading that, I didn't think those depictions were intended to be major and lasting redesigns for The New 52.
You probably already knew this, but in case you didn't, that's why he was like that.