PAOcn MEDIA MONITOR By STEVE K. WALZ-TELEVISION WRITER Cliffhangers insure ratings bonanza Stephen Carrington (Al Cortey, left) ponders hit future since his sister. Felon (Pemeie Sue Martin), hes given damaging testimony to support her father's (John Forsythe, right) claim that he did not murder Stephen's homosexual lover, on ABC'̂ jiPynasty." New York--Although viewer interest in prime-time series wanes a bit during the balmy summer months, the networks continue to experiment. It isn't unusual for a teetering program to be placed in a stronger timeslot in order to achieve a better sampling, thus earning a reprieve for another season or two. And, it is quite common for the networks to playback, i.e. re-run, their most popular cliffhang- ing serials hoping that the viewers of these programs will stick with it no mat ter where it ends up in the scheme of things in the fall. For those of you who have a keen in terest in what might happen to some of your favorite video characters, I've put together a brief synopsis culled from in formation supplied to me from various industry sources. ABC Happy Days--Richie and Lori Beth Cunningham will have a baby. Laverne and Shirley--It's possible that Lenny and Squiggy will bow out due to contractual problems. Three's Company--Another shapely lass will be added to the cast. The in-' dications are that she will be a Chrissy Snow clone. Too Close For Comfort--Two new ad ditions next season. Henry's off-beat niece will come to live with the family in San Francisco and Muriel will have a baby to heighten the household chaos. Greatest American Hero--Ralph and the G-Man will meet their Soviet counter parts. Dynasty--Will Blake Carrington be found guilty of murdering his son's homosexual lover? The final mystery witness to take the stand was a veiled woman, who supposedly was Carr- ington's first wife. Nobody knows who portrays this pivotal role and Spelling- Goldberg is keeping a tight lid on the identity of the actress. Could it be Natalie Wood or Stefanie Powers? Also, Bo Hopkins, who plays Matt Blaisdel, wants out of the show claiming that his role has been watered down. ABC execs are planning to add two new characters (male and female) to the cast. Love Boat--Will Julie McCoy marry her Aussie fiance? Probably not. Fantasy Island-- Herve Villechaize's contract problems could have his Tatoo character axed from the series in favor of a female sidekick for Mr. Roarke. Mork and Mindy--Mork will marry Mindy. They will honeymoon on Ork where Mork will become pregnant and give birth to a middle aged male said to be Jonathan Winters. Could be the most outrageous union in TV history. CBS Archie's Place-- Murray is gone so Ar chie must look for a new partner. One Day At A Time--Barbara might get married while Schneider may end up with Nick's kid. But if Pat Harrington reneges on a new contract, the whole series may be scrapped. Knots Landing--Does Sid Fairgate sur vive his auto mishap? Most probably and you can bet he'll be looking to go after J.R. Ewing. , Dallas--Speaking, of the dastardly Dallasite--who did he toss into Southfork's pool? I'd say it was Kristin. It can't be Leslie because the form floating face down in the pool had brown hair. And is she really dead or just un conscious? Sue Ellen is in deep trouble for getting Pam to kidnap J.R.'s son. And J.R.'s secretary has bitten the dust after failing to tell his business associate to get out of the country. Expect Lucy to ditch Mitch next year, too. NBC Flamingo Road--Does Constance sur vive the fall from the broken bannister? Of course she will, and you can bet that Fielding will be in for all kinds of trouble next year. It would appear that the Lane Ballou character will be diminished somewhat. There's also talk of adding a dashing new male character to heat things up in somnambulant Truro, Florida Little House--Melissa Sue Anderson wants out, so after three or four guest appearances her character will be drop ped out. Alison Arngrim wants to make movies, so Nasty Nellie will also be eliminated. TV COUP WOO ttWVWff. MC.