The 70-minute premiere is set in a stylish, stylized New Gotham, and it lays out how we got here and brings in the third member of the show's trio, a teenage girl who, when she was younger, saw the Joker's attacks on Batman's family in her dreams.
I've heard that we won't be seeing any other superheroes, though there may be hints about them from time to time. (There was a cute reference to people being "affected by meteor rocks," which keeps happening on "Smallville.") Batman has appeared only in flashbacks, but while we know what happened to Catwoman, we don't yet know where Batman is. No doubt they've left this loose thread so they can have fun with it later.
Of course, since it's a WB show, it's got attractive women and great (Warner-supplied) music. But, since it's in the Batman universe, it's got a suitably dark look and feel. (No primary colors for these superheroes.) Whether it'll last or not, I can't say, but I've decided it's worth another hour of my life when the second episode airs tomorrow night. (Of course, it's up against "West Wing," so I'll be recording the west-coast feed at midnight!)