Former CBS and CNN correspondent Deborah Potter, now president of the NewsLab takes on the conventional wisdom that the network evening newscasts are outdated and driving away younger viewers. Potter argues that while some "tinkering" is good "the nightly newscasts will never be what they once were — a national hearth around which Americans shared a daily experience."

More of Potter's thoughts after the jump...

The "good old days" of network news featured lots of white guys in ties standing in front of buildings in Washington. Today's reporters and stories are more diverse, and they make far better use of video and sound. CBS made the most visible attempt to reinvent the nightly news when Katie Couric came aboard as anchor last year. When commentary and live interviews didn't move the needle, they were dumped.

But CBS' failures haven't stopped the other networks from tinkering. This fall, in a subtle appeal to younger viewers, NBC dumped its nostalgic newscast open that paid tribute to anchors of the past from John Cameron Swayze to Tom Brokaw. Unfortunately, the new open is just trite. 'Nightly News begins now!' Well, duh.

That's not the only bad idea the networks have borrowed from local news lately. Think props and "live for the sake of live." When the makers of infant cold medicines recalled some of their products, CBS correspondent Wyatt Andrews was live from the Washington newsroom holding up a box for the camera. ABC's Lisa Stark went live from a drugstore.

...these aren't your parents' newscasts anymore. And that's not all bad.