It will be an end of an era for network evening news this week.

ABC's Diane Sawyer will sign off and make way for David Muir (Muir offically takes over on Septmeber 2nd). 

When Sawyer signs off, it will be back to the future for the network evening newscasts. Once again all three nets will have white guys doing news.

At one point, NBC's Brain Williams was the only white dude doing the evening newscast. Katie Couric was fronting the news at CBS and Sawyer was over at ABC.

After Sawyer signs off, it will be back to the all boys club.

Sawyer is leaving the chair, but not ABC news. She will focus on reporting, interviews and new programming as ABC tries to turn her into the next Barbara Walters.

Stay tuned....