If all goes according to schedule, Tom Cruise will appear tonight on “The Late Show with David Letterman” (10:35 p.m., CBS). I guess that should be interesting in a painful fashion. Both Cruise and Letterman gained national prominence in the early 1980s and have remained perched in our consciousness ever since. But neither man seems quite what he used to be – or even quite who he used to be.

In all honesty, I gave up “Letterman” years ago. His monologues and bits seem forced and repetitive. And not only are his interviews prepackaged and staged, Letterman has made a public point that his guests come prepared with a canned, well-rehearsed presentation. Few people have done more to destroy the art of conversation on television than David Letterman. The atmosphere of non-spontaneity on his show is often bleak and suffocating.

So Letterman and Cruise meet tonight, two popular and spectacularly overpaid symbols of an entertainment industry that is not only failing at it’s one clear mission (to attract and entertain an audience), but that is also beginning to endure open derision from a jaded public that’s too bored to go to the movies anymore.

Despite the best efforts of the industry’s most powerful flacks, Tom Cruise is suffering from a serious case of the Emperor’s New Clothes. Fewer and fewer people are buying his act. But with his stiff, robotic mannerisms and seemingly programmed personality, Cruise ought to feel right at home on David Letterman’s couch. Perhaps these two ’80s icons deserve each other.

Tonight’s other highlights

¢ “Declining by Degrees” (8 p.m., PBS) examines how uninspired students, overworked teaching assistants and jaded professors have created an academic atmosphere that rewards mediocrity.

¢ Tommy Hilfiger tries to clone a mini-me on “The Cut” (7 p.m., CBS).

¢ Grissom’s crew finds gruesome remains on “CSI” (8 p.m., CBS).

¢ San Antonio and Detroit meet in Game 7 of the NBA finals (8 p.m., ABC).

¢ Host Vernon Kay towers over the competition on “Hit Me Baby One More Time” (8 p.m., NBC).

¢ A new medication complicates a kidney transplant on “ER” (9 p.m., NBC).