I have been watching ER since episode 1 and haven’t missed a one of them. So that being said…just let it die. It was good, but it jumped the shark a LONG time ago.
This season has been especially lackluster with only a few pearls tossed in. (The Cynthia Nixon episode and the recent episode with the letters back and forth to Iraq.) So instead of extending just for the sake of extending it….let it die a graceful death.
And if Noah Wyle is really leaving at the end of the season, which is up in the air at the moment, what better is there to end it than with the departure of the character that started the series?
Sometimes you just have to know its time to cut and run. Sadly the ER folks didn’t.