On television, the battle of the sexes has entered a cold war phase. The men are now the preening peacocks and the women contemplate "getting lucky" before a foray into single's bardom. One wonders if we really have come a long way, baby, or just full circle - and if it's really so reactionary to prefer the days when Ginger slapped Fred's face in the first reel but had melted into submission by the last.

"Rollergirls" and "Joe and Valerie," two new NBC comedies starting trial runs tonight on Channel 4 at 8 and 8:30, pretend to be terribly trend-minded about changing sexual roles and modern mating rites, but both shows are so mechanical and strident that interest is defied at every turn and concern for the characters completely out of the question.

At least on "Joe and Valerie," obviously inspired by the success of "Saturday Night Fever," there are some attractive young performers on the loose, and on the make, including Paul Regina as Jo Pizo and Char Fontane as Valerie Sweetzer, the young lovers who meet at a disco and seem destined tot hustle through life together, or for the next four weeks anyway. The real scene stealer on the premiere is David Ellitt as the derivatively conceived but subtly played Paulie, shy guy among the disco hot-shots.

For a half-hour sit-com, this is a very elaborate production, shot partly on a giant flashing disco set. But neither the earthiness nor the latent desperation of the dancing is captured as well as they are on "Soul Train" or "American Bandstand," and the set just looks crowded with dancers, not throbbing with life. Some of the tape editing is awkward and the laugh track sloppy.

But the real problem with "Joe and Valerie" is that somebody forgot to write it - although producer Bernie Kahn is credited with the script. Nothing noticeable about Joe and Valerie distinguishes them from their crowd; they are ships that bump in the night but set off hardly a spark. We're supposed to respect Valerie because she isn't quite as hot to trot as her homely friend Thelma; at best, that makes her a type, and one not much different from Annette Funicello's in the beach blanket age or Jane Powell's in the frigid '40s.

"Rollergirls" is entirely dependent on its visual aids - the way the female stars look in their tight T-shirts. This is supposed to camouflage the flagrant stereotypes in the group, like the blond dumbbell played by Marcy Hanson or the tough-cookie bombshell played by Joanna Cassidy.

The show, from the James ("Kotter") Komack factory, premieres with a script full of last year's pseudo-feminist cliches, but star billing is given an obnoxious male, Terry Kiser, as the team's manager. The women get big yocks with such lines as, "Our fans are like a sperm whale - they're both endangered species" and by threatening to "bite two new holes in a male chauvinist's nose.

Both "Rollergirls" and "Joe and Valerie" boast Fonzie clones and try to exploit the sit-com myth that being "streetwise" is as good or better than being intelligent, or smart, or civil. This myth isn't limited to sit-com alone; it is everywhere on the air, and it's beginning to seem remotely dangerous as well as patently specious. It's blue-collar chic with a ring around the collar, and what it basically endorses and finds cute is hedonistic cloddishness.

Perhaps fortunately in these cases, the endrosement is stiff, dull and largely listless. 'Rostropovich'

America's cuddliest orchestra conductor is afforded an insultingly sugary testimonial tonight with "Meet Rostropovich, Maestro and Man," on Channel 9 at 7:30. If you think the Russian-born director of the National Symphony Orchestra has had too much media attention already, this miserably edited love letter will send you right over the brink.

The half-hour includes film of Rostropovich speaking almost inaudibly to a Catholic University class, rehearsing the National Symphony, and being interviewed as if he were the Pope of the musical world by a sycophantic talk show host named David Wholey.

"I watched you conduct the other day," Wholey says at one point. "Now, is that a sense of power?" This is his idea of a penetrating question. Rostropovich suffers the inanity patiently, and why shouldn't he? The half-hour is nothing but a paean to his "warmth" and "charm" and his love for music, the orchestra, and all that is dear and good in the world.

There is no mention of firings of long-time orchestra members and, since the interview was taped before the Soviet Union stripped Rostropovich of his citizenship, only outsiders get to comment on that.

Now and then, the show does try to make Rostropovich an issue as well as a living saint, but to little effect. Except for a tiny moment when the maestro's dog Pooks pokes at the keys of a grand piano, the program is a drowsy mess, and the reason for this is simple. The people who made it did not know what they were doing.