Yes, they definately do need to mix it up a bit. But these days the technical aspect of a show makes it more difficult to do that coz of the elaborate light show as it all has to be programmed in advance.
Sometimes the lighting director is up all night programmin' his lights for the show the next day, he has a few hours sleep before he has to go to work again to help set up the show for that night. Can you imagine how f*cked off he would get if it was all changed at the last minute?!

Anyhow, having said that, the only show for a long time which I was genuinely suprised with what was comin' next was Munich 2003!
And probably Shepherds Bush 2001. Shepherds bush was so damn great that I didn't even notice that they hadn't done KTF (my favourite) till they did it!