I disagree. I believe Flash and Wonder Woman each separately have more mass-appeal than all of those names combined. Most of DC's Heavy-Hitters or Heavyweights are recognized by those who don't even read comics. Hell, Aquaman himself gets more references than Namor (if he has even gotten one ever on a tv show, parody, film, book, etc) and Aquaman is portrayed as a joke, more often than not.
DC's marketability now lies in the fact that average joes know who Batman, Superman, Wonder Woman, Flash and Aquaman are without having read a single comic or been a fan of the character and/or genre. For instance, a Batman-Superman crossover on the big screen would be a gargantuan pop-culture/icon deal.
Right now, I only see Wolverine, Spiderman and now Iron Man as Marvel's only Heavy-Hitters. Circumstances can certainly change in a couple years but there's never guarantees in this business. Look at Green Lantern, Ghost Rider, Dare Devil, The Punisher, etc.
True, but TDK was the only CBM to cross two barriers (Oscar; Billion). Now, TDKR is riding off that momentum and steam, and it's not showing signs of slowing down. Chris Nolan is pushing the Batman's envelope yet again. He's taking it to places where no CBM has been before.
Whether or not TDKR will make a billion this time around, it's still the top dog in the yard and will be difficult to dethrone (in the genre) solely based on it's reputation from 2008.
That being said, I have a feeling that neither The Avengers, TDKR or TAS will make a billion. The Hobbit and Ice Age are probably destined to rule 2012. It doesn't help the case that we got another Twilight flick coming this year too.