Once again, ballet figures prominently among television's holiday offerings this year, a further sign that the dance boom hasn't yet loosened its hold on the masses.

Two major exhibits are juxtaposed across the weekend: On Christmas Eve (8 p.m.), CBS (Channel 9) rebroadcasts its last year's TV adaptation of Mikhail Baryshnikov's production of "The Nutcracker" for American Ballet Theatre (currentlu on view, live, at the Kennedy Center); on Christmas (8 p.m.) Channel 5 repeats the Metromedia BBC presentation of the Royal Ballet's "Sleeping Beauty" (with Baryshnikov as host), first transmitted by satellite last week. Both the advantages and drawbacks of ballet on the tube are amply illustrated by these programs.

The Royal Ballet's "Sleeping Beauty"-this is the most recent in a series of revamped stagings, under the supervision of Ninette de Valois-has two conspicuous merits. One is the rightfully renowned English sense of theater, which pervades the whole production; the other is David Walker's tastefully lavish period decor.

But the very size and sumptuousness of the affair works to its detriment on TV. The huge cast and pictorial vistas demand long shots much of the time, and the Lilliputian result on the confining screen diminishes not only the dancers but also their movement to the vanishing point. Merle Park as Aurora and David Wall as the Prince, moreover, are almost too English. Despite the elegance of their dancing, the staid reserve of their portrayals puts a chill on the romance that not even Tchaikovsky's music can entirely dispel.

The last act, which permits much closer viewing, brings vast improvement, and a stunning Bluebird pas de deux with Jennifery Penney andWayne Eagling makes it well worth the wait.

The CBS "Nutcracker" has one thing the live ABT staging doesn't-namely, Baryshnikov himself (he's since joined the NYC Ballet) partnering Gelsey Kirkland, and this is asset enough for any ballet fan. Tony Charmoli's glossy TV direction, however, is a mixed blessing, using the camera to canny effect in transitins and closeups, but marring both choreography and drama with jittery cutting and a souvenir-album facial fixation.