Transformers: Revenge of the Fallen and Ice Age 3 both saw estimates claiming that each made approximately $42.5 million over the three-day weekend. See the exact estimates here; sorry for the oxymoron.
It now looks like that Ice Age 3 took in less than $42 million over the three-day while Transformers 2 is still somewhere near $42.5 million. Close, but that's still a victory for Paramount.
Since I went the opposite way of critics and instead loved Transformers 2, I couldn't be happier with the numbers.