This post is for Adam Forgione!
Adam from Pennylane Productions just asked a question on facebook.
My answer was yes as long as we had some other type of main light. He also asked for examples.
Real fast I remembered two shots Ronnie took at a reception during the first dance and a random dance set.
Both images were shot around 5000 ISO and with the worlds greatest camera the nikon D3s!
So Adam the answer is yes, Good photographers can make it happen!
EDITED to add three more.