Yup, it turns it into a global catastrophe.
I'd have enjoyed the visual of the squid in downtown New York, I've seen New York zapped with lasers before, but I can see from how the new ending might enhance the story. I will wait and see what I think of it this weekend, but I understand why they changed it and am open to the concept.
A friend of mine here in Toronto worked on the IMAX transfer of the film and said the film is very good, so I'm optimistic. He got to see Star Trek the other day... sonofa...