Two-D or not 2-D, that is the question. Can traditional two-dimensional animation survive? Or will it merely fade away like vaudeville, radio and the credibility of network news, phased out by the surging popularity of three-dimensional computer generated imagery (CGI) ‘toons?

Ever since “Toy Story,” children and parents have flocked to CGI films, ignoring traditional cartoon fare like “Iron Giant” and relegating the once-powerful Disney animated musicals to second-rate status. The last Disney musical to make a splash was “Lilo and Stitch,” but its audience was chum compared with that of “Finding Nemo.”

Tonight, the wags at Nickelodeon declare a truce of sorts in the animation wars with a crossover episode of the cartoon “The Fairly OddParents” and the CGI hit “The Adventures of Jimmy Neutron” called the “The Jimmy/Timmy Power Hour” (7 p.m., Nickelodeon).

“Power Hour” deserves much credit for playing with cartoon formats and joking about the intersection of science and magic. But like many one-hour cartoon features, it is probably way too long for young attention spans and way too loud for grown-up endurance.

• “The Powerpuff Girls” (6 p.m., Cartoon Network) is one cartoon that has never had a problem amusing both adults and children. In tonight’s new episode, arch-villain Mojo Jojo becomes a language instructor at a junior college after receiving a court order to do community service. When the hyperverbose monkey madman’s special brand of elaborate English catches on, the city of Townsville is slowed to a linguistic crawl.
• Blondie performs on “Live By Request” (8 p.m., A&E). Fronted by Debbie Harry, Blondie was one of the few bands to emerge from the punk-rock scene and cross over into popular stardom. The New York band hit the charts with the disco-influenced 1978 single “Heart of Glass.” By 1979, Blondie was so mainstream it appeared on “The Muppet Show.”

Tonight’s other highlights

• An enraged dad (Gene Simmons) goes on an anti-cop rampage on “Third Watch” (9 p.m., NBC).
• Scheduled on “20/20” (9 p.m., ABC): interviews with Teresa Heinz Kerry and Kate Hudson.
• Scheduled on “On the Record with Bob Costas” (10 p.m., HBO): Hugh Jackman, Liz Phair, Spike Lee and Chuck D.

Late night

Kelsey Grammer, Orchestra Baobab and the latest “Survivor” evictee appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno welcomes Anna Nicole Smith on “The Tonight Show” (10:35 p.m., NBC) … Jenny McCarthy and Dr. Drew Pinsky appear on “Jimmy Kimmel Live” (11:05 p.m., ABC).

Lauren Graham chats on “Late Night with Conan O’Brien” (11:35 p.m., NBC) … Carl Reiner, Saffron Burrows and Elefant appear on “The Late, Late Show with Craig Kilborn” (11:37 p.m., CBS).