Even as the traditional month of fall television premieres arrived, network execs had little to show for it — literally.

Labor Day passed, and ABC had yet to show critics and advertisers its reworked take on the U.K. hit “Life on Mars.” NBC promoted the hell out of shows like “Kath & Kim” and “My Own Worst Enemy” during the Beijing Summer Olympics — yet were still retooling the shows, leaving the world wondering what those frosh entries were all about.

And then there was the CW’s much-heralded revival of Fox’s “90210” — which was shot so close to the fall that the netlet decided to keep the show under wraps (and away from TV critic scrutiny) until its Sept. 2 launch.

“Certainly the strike changed everything in terms of the way development went,” says ABC Entertainment prexy Steve McPherson.

Fall 2008 is shaping up to be the strangest premiere season on record, as the networks continue to readjust their timetables post-writers strike. The fact that the work stoppage — which was resolved in February, seven months ago — still reverberates says a lot about the fragile state of the TV biz.

The nets each took different approaches toward handling development and pilot season after the strike, which explains why they all seem to be at different stages heading into the new season. Besides revamps on shows like “Kath & Kim” and “Enemy,” Alphabet’s “Mars” also received a top-to-bottom makeover.

That’s also why crix are still waiting, so far in vain, for a glimpse at most new series.

“It’s a huge problem for me, and I know for a lot of other critics,” Sacramento Bee commentator Rick Kushman told Variety last month.

CBS was able to provide the most business-as-usual face at the May upfront presentations, having scrambled to shoot as many pilots or presentations as possible. As a result, the Eye had full-fledged clips to show advertisers — and was able to send out screeners to journos before the TV Critics Assn. press tour in July.

“We needed to have new content, new programming available for our audience this fall,” says CBS Entertainment prexy Nina Tassler. “It was really important to give them something to look forward to, something to anticipate.”

NBC also announced a fall sked chockful of new skeins — but unlike CBS, the Peacock picked up many of its new series sight unseen. Some shows were picked up sans pilot, while others were greenlit as co-productions with international partners, such as “Crusoe.”

“The strike, by necessity, forced us to look in places that we didn’t look before as much, and we found that we liked what we saw,” says NBC Entertainment/Universal Media Studios co-chairman Marc Graboff. “Time will tell what works and what doesn’t work. But going back to the old way of doing business, with the seasonal development season … that doesn’t work anymore.”

The CW, similarly, greenlit the centerpiece of its fall campaign, “90210,” without a single lick of tape. Actually, the show was adding cast members the same day the network was shooting promo material for its upfront presentation.

ABC and Fox, meanwhile, needed very little new product in the fall — allowing both nets to take their time and continue developing leftover pilots well into the summer.

For Fox, it was pretty much business as usual: The net had already cut down on its fall preems in recent years — having been in the past hampered by baseball playoff preemptions. This fall, Fox only picked up one drama (“Fringe”), one laffer (“Do Not Disturb”) and one reality skein (“Hole in the Wall”).

ABC picked up two new skeins for fall — “Mars” and reality series “Opportunity Knocks” — in order to bring back several promising series from last year. That includes “Pushing Daisies,” “Dirty Sexy Money” and “Private Practice.”

“We felt that we had a dominant fall and a real strong core schedule, so we didn’t need that much new programming,” McPherson says. “And we also decided really early on that we weren’t going to announce in May shows that didn’t exist, that hadn’t been developed or shot or piloted and gone though the regular process.

“It’s an odd year. The rhythms have changed.”

Even NBC finds itself more heavily promoting its returning fare. During the Olympics, Peacock said 65% of its promo time was focused on veteran series, while just 35% was earmarked for new shows.

That shift toward returning series is also born out of necessity: Network marketing execs are having a tough time coming up with campaigns for shows that are still being reworked.

“It’s a big challenge for us,” Alphabet marketing exec VP Mike Benson told Variety last month. “I’ve never had a situation like this fall where I don’t have a show’s pilot yet.”