Today on TV

Joan of Arcadia (7 p.m., Ch. 2): They're not praying for better ratings for this show — yet. But the numbers have declined significantly this season and there's no guarantee it will return for Season 3. "We still love the show," said CBS Entertainment president Nina Tassler, "and we're big, big supporters of it. Clearly, we had to take a look at it and make some creative adjustments. The network is "launching two big marketing campaigns" and doing some "great stunt-casting," including bringing in Hillary Duff for tonight's episode. "It clearly is a show that we're very proud of. When we're criticized about not taking risks in television, this show was that risk." Tassler said.

College volleyball (7 p.m., Ch. 11): UCLA at BYU

Bernie Mac (7 and 7:30 p.m., Ch. 13): A new episode, followed by a repeat.

Star Trek: Enterprise (7 p.m., Ch. 24): The ship is attacked by Romulans.

Grounded for Life (7:30 p.m., Ch. 30): Claudia goes into labor in the series finale.

Hope & Faith (8 p.m., Ch. 4): The sisters open a catering business.

Jonny Zero (8 p.m., Ch. 13): Jonny helps a teenage girl learn to box. (His "Million Dollar Baby"?)

Reba (8 p.m., Ch. 30): Van hires a nanny.

Monk (8 p.m., USA): Did a dead man commit murder?

Numb3rs (9 p.m., Ch. 2): The new series moves to its regular time slot.

Medical Investigation (9 p.m., Ch. 5): A brain disease afflicts Arctic scientists.