David Letterman is reportedly in talks to extend his CBS contact beyond 2010. The idea is to take ratings from Conan O'Brien's Tonight Show; further taunting Jay Leno is a fringe benefit.

Letterman wrangled unsuccessfully with Leno for the Tonight Show 18 years ago. After Leno announced he would move to a new 10 pm show, Letterman started making jokes about the time slot on the Late Show. See the compilation at left!

Letterman must also relish the latest development, as reported tonight by Broadcasting & Cable: CBS executives are said to be interested in re-upping with Letterman when his contract expires in 2010. Reports B&C:

The two sides are striking up talks as the 11:30 timeslot is about to undergo a sea change with Conan O'Brien taking over The Tonight Show and Jay Leno deciding not to jump to ABC and compete for those viewers.

Letterman has backed off from his 10 p.m. jokes in recent weeks; the attached clips above are from December. But once Leno gets close to actually making the 10 p.m. move, Letterman is likely to bring them back more relentlessly than ever, particularly if CBS doubles down on him. TV-feud connoisseurs should certainly hope so.