This just in from Variety:

Tom Poston, who won an Emmy on The Steve Allen Show and was Emmy-nominated for Newhart, Mork and Mindy and Coach, died on Monday after a brief illness. He was 85. While best known for playing George Utley on Newhart and for making guest appearances on The Bob Newhart Show, Poston also had roles in a number of Broadway productions and touring companies (e.g., A Funny Thing Happened on the Way to the Forum, Bye, Bye Birdie), and his film credits included Princess Diaries II and Soldier in the Rain.

Poston is survived by his wife of six years, Suzanne Pleshette (also of Newhart fame), and two grown children from his second marriage. Donations may be made to the Motion Picture and Television Fund.

Matt here. For my money, Poston was one of television comedy's great go-to guys, always at the ready with the beleaguered, sheepish or hangdog look/line delivery. He will be missed.