TV viewers hooked on cliffhanger episodes of hit shows such as Heroes and Grey's Anatomy could be left dangling if writers walk off the job.

With Hollywood writers poised to go on strike as soon as Thursday, TV networks were bracing for the need to fill time with reality shows, game shows, even reruns.

Viewers could start seeing an onslaught of unscripted entertainment by early next year, when series such as Desperate Housewives and Heroes run out of episodes.

"I was in a network meeting (Monday), and they were referring to the fact the timing is good for reality producers," reality TV producer Mark Cronin said.

"It's going from 50 mph to 70 mph," Cronin said, adding that networks must "protect themselves and fill their airspace" amid the upcoming writers strike.

The Writers Guild of America and the group representing film and TV producers were set to meet this week with a federal mediator after contentious talks.

With the contract set to expire at midnight Wednesday, negotiators remain far apart on the central issue of raising payment for profits on DVDs and TV shows offered digitally on the Internet, cellphones and other devices.

A newcomer to TV's writing ranks earns about $70,000 per season for full-time work on a show like Grey's Anatomy, Desperate Housewives or Heroes.

Veteran TV show writers who move up to a story-editor position would get at least a low six-figure salary, with a "written by" credit on an hour-long script paying an additional $30,000 plus residuals.

Writers are free to negotiate for higher pay, and people who produce or co-produce - called "hyphenates" in industry parlance - earn more.

If writers walk out, the effect wouldn't be felt immediately. Networks have enough episodes of shows like CSI and Ugly Betty written and in production to last at least the end of the year and possibly into February of 2008.

After that, most schedules will run into trouble.

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.