Laura Palmer lives!

Not exactly, perhaps, but Monday`s announcement that ''Twin Peaks'' will return in the fall as a regular ABC series at 9 p.m. Saturdays does ensure that one of the most unusual experiments in TV history will continue, in some fashion, to exist.

This news makes the show`s 9 p.m. Wednesday episode-the final installment of its seven-week run-somewhat less the event that it might have been. Now, of course, it doesn`t matter if we discover who murdered Laura (or if she`s really dead). We can always see in September.

Too bad. I think ''Twin Peaks'' should not-that`s right not-be returning as a regular series.

Hear me out. I love the show, have spent each of the last six Thursday nights glued to the tube and, each Friday morning, have discussed what I saw there at length. (It`s airing this Wednesday so that ABC can capitalize on the last day of the Nielsen-measured sweeps.)

I have also spent much of the last six weeks answering questions from people who wanted to know if Laura`s killer will be uncovered; if agent Cooper is an extraterrestrial; and what`s the deal with the coffee and pies. Then there were the calls from reporters from various magazines who were eager to know where they could locate ''Twin Peaks'' fan clubs.

The excitement was understandable. Created by filmmaker David Lynch and

''Hill Street Blues'' veteran Mark Frost, ''Twin Peaks'' brought to TV something with a feature-film feel. It was full of sex, strange themes, stranger characters, unpredictable twists and off-the-wall humor.

The show contained elements that enriched the TV landscape. And in its ability to be thought-provoking, it was good for network TV, and its influence surely will be felt.

I can`t blame ABC for wanting it to return. There`s little doubt that if ABC didn`t renew the show, the aggressive Fox network would have picked it up. Additionally, ''Twin Peaks'' is an important link in ABC`s five-year plan for rebuilding the network.

Though the show`s ratings dropped precipitously after its two-hour premiere, they have recently leveled off. And the demographics are strong:

Though it attracts a relatively modest 18 to 19 percent of available viewers

(good numbers, considering the competition from NBC`s highly rated

''Cheers''), the program`s audience consists of huge numbers of younger women viewers, the audience that advertisers covet most.

But all of the rational reasons, however justifiable, cannot make me think that whatever we see on ''Twin Peaks'' in the fall will not appear commonplace to what we`ve seen over the last weeks.

It will never be as exciting, stimulating or rewarding as was the ''Twin Peaks'' we have known so far. What we have known was essentially an episodic movie, and transforming it into a series presents a number of problems.

There has never been a successful movie-to-TV transfer, and though Lynch and Frost will undoubtedly play a role in developing and shaping the ''Twin Peaks'' series, their week-to-week involvement is sure to be limited by the press of other projects on their agendas.

They certainly created the recipe to intrigue the public, but will the people they put in charge of the creative kitchen be able to work similar magic? I doubt it.

''Twin Peaks'' was created from a distinctive, shared mutual vision that offered surprises at every turn.

Spending time with the ''Twin Peaks'' that concludes Wednesday was like a great vacation in a place you`ve never been. Watching the series, I`m afraid, will be like looking at pictures of that vacation-interesting, perhaps evocative, but without the fire of being fresh.

`DEAD RECKONING` 8 P.M., WEDNESDAY, USA

Rick Springfield, never my cup of dramaturgical tea, turns in a good performance in this suprisingly solid made-for-USA-cable-movie.

He plays the former lover of Susan Blakely, who has bought her husband, a wealthy Seattle plastic surgeon played by Cliff Robertson, a luxurious sailboat. And who should be at the helm? Why, Springfield; and when the three of them are stranded during a storm at an abandoned lighthouse, things start to sizzle sexually and boil with muder plots and double crosses.

It`s a beautiful-looking movie, filmed in the Vancouver area, and nicely acted by all involved but especially Springfield, who`s full of snaky menace. `HOW TO MURDER A MILLIONAIRE` 8 P.M., WEDNESDAY, CBS

There is one section in the middle of this miserable movie when Joan Rivers, in a twist of plot that defies the imagination, is working as a maid. Her grimacing and mugging are so outlandish that one turns away in disgust. And the rest of the package is hardly better.

Believing her husband (Alex Rocco) is trying to kill her, Rivers splits and gets invloved with a con woman (Telma Hopkins) and her ''regular person`s'' life. Also starring Meshach Taylor, Morgan Fairchild and David Ogden Stiers, this is the sort of movie that could give Joan Rivers` insipid talk show a good name.