I didn't know about this either, and as I was preparing to get up for the standing O, the houselights came up and I was like "Oh...alright."
It's great if the standing ovation comes from the mezzanine, but what if you're in the orchestra? I think it'll be too disctracting for those not aware of the lack of curtain call, with some people standing up and those around you getting pissed. And then if you're short, you won't get to see the finale at all!
I totally get why it's done this way, but I'm with those that feel a slight change would do to acknowledge to the audience "hey, last chance to applaud!"
"Hey little girls, look at all the men in shiny shirts and no wives!" - Jackie Hoffman, Xanadu, 19 Feb 2008