TV tonight: 'Dr. Horrible,' 'The Voice,' 'NCIS: LA'

• 'The Voice' moves to the updated "battle" rounds
• 'NCIS: LA' welcomes the mothers of its stars
• 'Dr. Horrible's Sing-Along Blog' moves from the Web to TV

The Voice
NBC, 8 ET/PT

The Voice continues its newly reformatted "battle" rounds, which now allow rival coaches to "steal" the losing singers for their own teams. While it's true the show had to do something to goose interest after its auditions, this change once again moves the focus to the judges at the expense of the singers, which is one of the reasons The Voice's popularity has not yet translated to recording success for the show's winners. And the longer that continues, the less interested viewers will become in the contest.

NCIS: LA
CBS, 9 ET/PT

Mother's Day comes early on NCIS' L.A. spinoff with an episode that features guest appearances by the real-life mothers of Chris O'Donnell, LL Cool J, Daniela Ruah and Eric Christian Olsen. Obviously, it's a publicity stunt, and it almost certainly has very little to do with the plot -- an intel leak that leads to the murder of four people at a diner. Still, as stunts go, it's kind of a sweet one.

Dr. Horrible's Sing-Along Blog
CW, 9 ET/PT

Most projects made for the Web are best off staying there -- but not Dr. Horrible, Joss Whedon's ingeniously witty, musical comic book spoof about a lonely young man who yearns to get the girl. Oh, and become a super-villain. Neil Patrick Harris is Dr. Horrible, Nathan Fillion is his thick-headed nemesis, Captain Hammer -- and the entire project is a clever, well-honed delight that, like every Whedon project, benefits from its creator's generous expenditure of talent, intelligence and craft. The budget may have been Web-sized; the entertainment value is not.